Add click animation completion code after a cell is deleted (well, re…

…ally hidden after a delete row animation without being deallocated to be reused later). Fix issue MortimerGoro#91 supposed to be caused by a null cell.indexPath because the callback was called while/after a cell is deleted

MGSwipeTableCell/MGSwipeTableCell.m

@@ -1205,7 +1205,10 @@ -(void) panHandler: (UIPanGestureRecognizer *)gesture
                 backgroundColor = expansion.backgroundColorCopy; //keep expansion background color
                 expansion.backgroundColorCopy = expSettings.expansionColor;
             }
-            [self setSwipeOffset:_targetOffset animation:expSettings.triggerAnimation completion:^{
+            [self setSwipeOffset:_targetOffset animation:expSettings.triggerAnimation completion:^(BOOL finished){
+                if (!finished || self.hidden) {
+                    return; //cell might be hidden after a delete row animation without being deallocated (to be reused later)
+                }
                 BOOL autoHide = [expansion handleClick:expandedButton fromExpansion:YES];
                 if (autoHide) {
                     [expansion endExpansionAnimated:NO];