Avoid script injection unless the JS engine is inferred to be Firefox's.

Former-commit-id: 1e267374fe85a858197609b35b85670394c0b66d

lodash.js

@@ -348,7 +348,8 @@
   };
 
   try {
-    createFunction();
+    // use script injection if Firefox's script engine is detected
+    (/1/.test(function(){1}) || createFunction)();
   } catch(e) {
     createFunction = Function;
   }