msglist [nfc]: Renamed speedLimitMs as variable refers to a duration rather than velocity

Author: sirpengi

lib/widgets/message_list.dart

@@ -240,8 +240,8 @@ class ScrollToBottomButton extends StatelessWidget {
 
   Future<void> _navigateToBottom() async {
     final distance = scrollController.position.pixels;
-    final speedLimitMs = (1000 * distance / 8000).ceil();
-    final durationMs = max(300, speedLimitMs);
+    final durationMsAtSpeedLimit = (1000 * distance / 8000).ceil();
+    final durationMs = max(300, durationMsAtSpeedLimit);
     scrollController.animateTo(
       0,
       duration: Duration(milliseconds: durationMs),