add graphite multiplySeries function

public/app/plugins/datasource/graphite/gfunc.js

@@ -87,6 +87,13 @@ function (_, $) {
     category: categories.Calculate,
   });
 
+  addFuncDef({
+    name: 'multiplySeries',
+    params: optionalSeriesRefArgs,
+    defaultParams: ['#A'],
+    category: categories.Calculate,
+  });
+
   addFuncDef({
     name: 'asPercent',
     params: optionalSeriesRefArgs,