update loading-sm.gif

ruoyi-admin/src/main/resources/static/ajax/libs/bootstrap-fileinput/fileinput.css

@@ -433,7 +433,7 @@
 }
 
 .file-uploading {
-    background: url(../img/loading-sm.gif) no-repeat center bottom 10px;
+    background: url(loading-sm.gif) no-repeat center bottom 10px;
     opacity: 0.65;
 }