fix[element-variables]: missing space in element-variables (#3144)

src/styles/element-variables.scss

@@ -6,7 +6,7 @@
 /* theme color */
 $--color-primary: #1890ff;
 $--color-success: #13ce66;
-$--color-warning: #FFBA00;
+$--color-warning: #ffba00;
 $--color-danger: #ff4949;
 // $--color-info: #1E1E1E;
 
@@ -17,10 +17,10 @@ $--button-font-weight: 400;
 $--border-color-light: #dfe4ed;
 $--border-color-lighter: #e6ebf5;
 
-$--table-border:1px solid#dfe6ec;
+$--table-border: 1px solid #dfe6ec;
 
 /* icon font path, required */
-$--font-path: '~element-ui/lib/theme-chalk/fonts';
+$--font-path: "~element-ui/lib/theme-chalk/fonts";
 
 @import "~element-ui/packages/theme-chalk/src/index";