Disallow invalid inline style comments in stylesheets (#9099)

res/css/views/rooms/_JumpToBottomButton.pcss

@@ -19,12 +19,12 @@ limitations under the License.
 .mx_JumpToBottomButton {
     z-index: 1000;
     position: absolute;
-    // 12 because height is 50 but button is only 38 = 12+(50-38) = 24
+    /* 12 because height is 50 but button is only 38 = 12+(50-38) = 24 */
     bottom: 12px;
     right: 24px;
     width: 38px;
-    // give it a fixed height so the badge doesn't make
-    // it taller and pop upwards when visible
+    /* give it a fixed height so the badge doesn't make */
+    /* it taller and pop upwards when visible */
     height: 50px;
     text-align: center;
 }
@@ -37,8 +37,8 @@ limitations under the License.
     font-size: $font-12px;
     line-height: $font-14px;
     text-align: center;
-    // to be able to get it centered
-    // with text-align in parent
+    /* to be able to get it centered */
+    /* with text-align in parent */
     display: inline-block;
     padding: 0 4px;
     color: $accent-fg-color;