change prompt wording on validation code

index.js

@@ -2780,7 +2780,7 @@ class ValidationView extends React.PureComponent {
           </label>
         </div>
         <div className="panel-form-row">
-        <input type="text" id="enter-confirmation-code" placeholder="The code is 123456"
+        <input type="text" id="enter-confirmation-code" placeholder="Numbers only"
           value={this.state.code} onChange={this.handleChange}
           onKeyPress={this.handleKeyPress} required />
         </div>

package.json

@@ -1,7 +1,7 @@
 {
   "name": "tinode-webapp",
   "description": "Tinode Web Client",
-  "version": "0.15.5rc6",
+  "version": "0.15.5rc7",
   "devDependencies": {
     "babel-cli": "^6.26.0",
     "babel-minify": "^0.4.3",