Fix crash

SessionMessagingKit/Jobs/JobQueue.swift

@@ -47,7 +47,7 @@ public final class JobQueue : NSObject, JobDelegate {
     }
 
     public func handleJobSucceeded(_ job: Job) {
-        JobQueue.currentlyExecutingJobs.remove(job.id!)
+        given(job.id) { JobQueue.currentlyExecutingJobs.remove($0) }
         SNMessagingKitConfiguration.shared.storage.write(with: { transaction in
             SNMessagingKitConfiguration.shared.storage.markJobAsSucceeded(job, using: transaction)
         }, completion: {
@@ -56,7 +56,7 @@ public final class JobQueue : NSObject, JobDelegate {
     }
 
     public func handleJobFailed(_ job: Job, with error: Error) {
-        JobQueue.currentlyExecutingJobs.remove(job.id!)
+        given(job.id) { JobQueue.currentlyExecutingJobs.remove($0) }
         job.failureCount += 1
         let storage = SNMessagingKitConfiguration.shared.storage
         guard !storage.isJobCanceled(job) else { return SNLog("\(type(of: job)) canceled.") }
@@ -78,7 +78,7 @@ public final class JobQueue : NSObject, JobDelegate {
     }
 
     public func handleJobFailedPermanently(_ job: Job, with error: Error) {
-        JobQueue.currentlyExecutingJobs.remove(job.id!)
+        given(job.id) { JobQueue.currentlyExecutingJobs.remove($0) }
         job.failureCount += 1
         let storage = SNMessagingKitConfiguration.shared.storage
         storage.write(with: { transaction in