CR: assign gutter trailing/leading in HeaderView

// FREEBIE

Signal/src/ViewControllers/ConversationView/Cells/OWSMessageCell.m

@@ -151,8 +151,8 @@ NS_ASSUME_NONNULL_BEGIN
         [self.contentView addSubview:self.headerView];
         [self.viewConstraints addObjectsFromArray:@[
             [self.headerView autoSetDimension:ALDimensionHeight toSize:headerHeight],
-            [self.headerView autoPinLeadingToSuperviewMarginWithInset:self.conversationStyle.headerGutterLeading],
-            [self.headerView autoPinTrailingToSuperviewMarginWithInset:self.conversationStyle.headerGutterTrailing],
+            [self.headerView autoPinEdgeToSuperviewEdge:ALEdgeLeading],
+            [self.headerView autoPinEdgeToSuperviewEdge:ALEdgeTrailing],
             [self.headerView autoPinEdgeToSuperviewEdge:ALEdgeTop],
             [self.messageBubbleView autoPinEdge:ALEdgeTop toEdge:ALEdgeBottom ofView:self.headerView],
         ]];

Signal/src/ViewControllers/ConversationView/Cells/OWSMessageHeaderView.m

@@ -93,8 +93,8 @@ const CGFloat OWSMessageHeaderViewDateHeaderVMargin = 23;
         [self.strokeView autoSetDimension:ALDimensionHeight toSize:strokeThickness],
 
         [self.stackView autoPinEdgeToSuperviewEdge:ALEdgeTop],
-        [self.stackView autoPinEdgeToSuperviewEdge:ALEdgeLeading],
-        [self.stackView autoPinEdgeToSuperviewEdge:ALEdgeTrailing],
+        [self.stackView autoPinEdgeToSuperviewEdge:ALEdgeLeading withInset:conversationStyle.headerGutterLeading],
+        [self.stackView autoPinEdgeToSuperviewEdge:ALEdgeTrailing withInset:conversationStyle.headerGutterTrailing]
     ];
 }