Observe YapDatabaseModifiedExternallyNotification.

Signal/src/ViewControllers/ConversationView/ConversationViewController.m

@@ -291,6 +291,10 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
                                              selector:@selector(yapDatabaseModified:)
                                                  name:YapDatabaseModifiedNotification
                                                object:nil];
+    [[NSNotificationCenter defaultCenter] addObserver:self
+                                             selector:@selector(yapDatabaseModified:)
+                                                 name:YapDatabaseModifiedExternallyNotification
+                                               object:nil];
     [[NSNotificationCenter defaultCenter] addObserver:self
                                              selector:@selector(applicationWillEnterForeground:)
                                                  name:UIApplicationWillEnterForegroundNotification

Signal/src/ViewControllers/HomeViewController.m

@@ -136,6 +136,10 @@ typedef NS_ENUM(NSInteger, CellState) { kArchiveState, kInboxState };
                                              selector:@selector(yapDatabaseModified:)
                                                  name:YapDatabaseModifiedNotification
                                                object:nil];
+    [[NSNotificationCenter defaultCenter] addObserver:self
+                                             selector:@selector(yapDatabaseModified:)
+                                                 name:YapDatabaseModifiedExternallyNotification
+                                               object:nil];
 }
 
 - (void)dealloc

Signal/src/ViewControllers/OWSLinkedDevicesTableViewController.m

@@ -66,7 +66,10 @@ int const OWSLinkedDevicesTableViewControllerSectionAddDevice = 1;
                                              selector:@selector(yapDatabaseModified:)
                                                  name:YapDatabaseModifiedNotification
                                                object:self.dbConnection.database];
-
+    [[NSNotificationCenter defaultCenter] addObserver:self
+                                             selector:@selector(yapDatabaseModified:)
+                                                 name:YapDatabaseModifiedExternallyNotification
+                                               object:self.dbConnection.database];
 
     self.refreshControl = [UIRefreshControl new];
     [self.refreshControl addTarget:self action:@selector(refreshDevices) forControlEvents:UIControlEventValueChanged];

Signal/src/ViewControllers/ThreadViewHelper.m

@@ -72,6 +72,10 @@ NS_ASSUME_NONNULL_BEGIN
                                                  selector:@selector(yapDatabaseModified:)
                                                      name:YapDatabaseModifiedNotification
                                                    object:database];
+        [[NSNotificationCenter defaultCenter] addObserver:self
+                                                 selector:@selector(yapDatabaseModified:)
+                                                     name:YapDatabaseModifiedExternallyNotification
+                                                   object:database];
     }
     return _uiDatabaseConnection;
 }

SignalServiceKit/src/Messages/OWSMessageManager.m

@@ -125,6 +125,10 @@ NS_ASSUME_NONNULL_BEGIN
                                              selector:@selector(yapDatabaseModified:)
                                                  name:YapDatabaseModifiedNotification
                                                object:nil];
+    [[NSNotificationCenter defaultCenter] addObserver:self
+                                             selector:@selector(yapDatabaseModified:)
+                                                 name:YapDatabaseModifiedExternallyNotification
+                                               object:nil];
 }
 
 - (void)yapDatabaseModified:(NSNotification *)notification