修复 transition 修改背景色示例多个;号在web平台上不生效的问题

(cherry picked from commit 4b26c255)

pages/CSS/transition/transition.uvue

@@ -159,7 +159,7 @@
       changeBackground2() {
         this.styleBackground2?.style?.setProperty("background-color", this.isTransitionstyleBackground2
           ? 'brown'
-          : 'rgba(0, 0, 0, 0.5);'
+          : 'rgba(0, 0, 0, 0.5)'
         )
         this.isTransitionstyleBackground2 = !this.isTransitionstyleBackground2
       },