i18n the title of the set mxid dialog

src/components/views/dialogs/SetMxIdDialog.js

@@ -251,7 +251,7 @@ export default React.createClass({
         return (
             <BaseDialog className="mx_SetMxIdDialog"
                 onFinished={this.props.onFinished}
-                title="To get started, please pick a username!"
+                title={_t('To get started, please pick a username!')}
             >
                 <div className="mx_Dialog_content">
                     <div className="mx_SetMxIdDialog_input_group">

src/i18n/strings/en_EN.json

@@ -571,6 +571,7 @@
     "To configure the room": "To configure the room",
     "to demote": "to demote",
     "to favourite": "to favourite",
+    "To get started, please pick a username!": "To get started, please pick a username!",
     "To invite users into the room": "To invite users into the room",
     "To kick users": "To kick users",
     "To link to a room it must have <a>an address</a>.": "To link to a room it must have <a>an address</a>.",