Fix SvgPrepPlugin

Author: romanbsd

Parse-Dashboard/public/favicon.ico

@@ -23,9 +23,9 @@ function SvgPrepPlugin(options) {
 }
 
 SvgPrepPlugin.prototype.apply = function(compiler) {
-  compiler.hooks.emit.tap('SvgPrepPlugin', compilation => {
+  compiler.hooks.emit.tapAsync('SvgPrepPlugin', (compilation, callback) => {
     if (!this.options.source) {
-      return;
+      return callback();
     }
 
     // TODO: Keep track of file hashes, so we can avoid recompiling when none have changed
@@ -43,6 +43,8 @@ SvgPrepPlugin.prototype.apply = function(compiler) {
             return sprited.length;
           }
         };
+
+        callback();
       });
   });
 }