Fixed issue with some sheets hanging around when the database is locked

MacPass/MPDocument.m

@@ -413,6 +413,9 @@ NSString *const MPDocumentGroupKey                            = @"MPDocumentGrou
    */
   // only lock if we do not have user interaction that cannot be dismissed!
   if(!self.lockedForFileChange) {
+    for(NSWindow *sheet in [self windowForSheet].sheets) {
+      [[self windowForSheet] endSheet:sheet];
+    }
     [self saveDocumentWithDelegate:self didSaveSelector:@selector(_lockDatabaseForDocument:didSave:contextInfo:) contextInfo:NULL];
   }
 }