lib: make extend writable

QuickBase has started to utilize angular which attempts to create the
extend utility and crashes hard when it can't...

Author: tflanagan

quickbase.browserify.min.js

@@ -39,6 +39,7 @@ if (!Object.hasOwnProperty('extend') && Object.extend === undefined) {
 
 	Object.defineProperty(Object.prototype, 'extend', {
 		enumerable: false,
+		writable: true,
 		value: function value() {
 			if (!warned) {
 				warned = true;

quickbase.es5.js

@@ -28,6 +28,7 @@ if (!Object.hasOwnProperty('extend') && Object.extend === undefined) {
 
 	Object.defineProperty(Object.prototype, 'extend', {
 		enumerable: false,
+		writable: true,
 		value() {
 			if (!warned) {
 				warned = true;