Revert "clean up escapePercentSign (#1101)"

Closes #1115
This reverts commit a1375754f9.

lib/dom-to-image.js

@@ -327,8 +327,9 @@
         node.setAttribute('xmlns', 'http://www.w3.org/1999/xhtml')
         return new XMLSerializer().serializeToString(node)
       })
-      .then(util.escapeXhtml)
-      .then(str => (escapePercentSign ? str.replace(/%/g, '%25') : str))
+      .then(function (str) {
+        return util.escapeXhtml(str, escapePercentSign)
+      })
       .then(function (xhtml) {
         return '<foreignObject x="0" y="0" width="100%" height="100%">' + xhtml + '</foreignObject>'
       })
@@ -551,7 +552,10 @@
       return array
     }
 
-    function escapeXhtml(string) {
+    function escapeXhtml(string, escapePercentSign) {
+      if (escapePercentSign) {
+        string = string.replace(/%/g, '%25')
+      }
       return string.replace(/#/g, '%23').replace(/\n/g, '%0A')
     }