Add Pinterest link previews.

SignalServiceKit/src/Messages/Interactions/OWSLinkPreview.swift

@@ -788,7 +788,7 @@ public class OWSLinkPreview: MTLModel {
         }
 
         var title: String?
-        if let rawTitle = NSRegularExpression.parseFirstMatch(pattern: "<meta\\s+property\\s*=\\s*\"og:title\"\\s+content\\s*=\\s*\"(.*?)\"\\s*/?>",
+        if let rawTitle = NSRegularExpression.parseFirstMatch(pattern: "<meta\\s+property\\s*=\\s*\"og:title\"\\s+[^>]*content\\s*=\\s*\"(.*?)\"\\s*[^>]*/?>",
                                                               text: linkText,
                                                               options: .dotMatchesLineSeparators) {
             if let decodedTitle = decodeHTMLEntities(inString: rawTitle) {
@@ -801,7 +801,7 @@ public class OWSLinkPreview: MTLModel {
 
         Logger.verbose("title: \(String(describing: title))")
 
-        guard let rawImageUrlString = NSRegularExpression.parseFirstMatch(pattern: "<meta\\s+property\\s*=\\s*\"og:image\"\\s+content\\s*=\\s*\"(.*?)\"\\s*/?>", text: linkText) else {
+        guard let rawImageUrlString = NSRegularExpression.parseFirstMatch(pattern: "<meta\\s+property\\s*=\\s*\"og:image\"\\s+[^>]*content\\s*=\\s*\"(.*?)\"[^>]*/?>", text: linkText) else {
             return OWSLinkPreviewContents(title: title)
         }
         guard let imageUrlString = decodeHTMLEntities(inString: rawImageUrlString)?.ows_stripped() else {