get rid of two-factor image folder

src/popup/app/accounts/views/accountsLoginTwoFactor.html

@@ -86,7 +86,7 @@
     <div class="content">
         <div class="two-factor-key-page">
             <p>{{i18n.insertYubiKey}}</p>
-            <img src="../../../images/two-factor/yubikey.jpg" alt="" class="img-rounded img-responsive" />
+            <img src="../../../images/yubikey.jpg" alt="" class="img-rounded img-responsive" />
         </div>
         <div class="list">
             <div class="list-section">
@@ -125,7 +125,7 @@
             <p ng-if="!u2fReady">Loading...</p>
             <div ng-if="u2fReady">
                 <p>{{i18n.insertU2f}}</p>
-                <img src="../../../images/two-factor/u2fkey.jpg" alt="" class="img-rounded img-responsive" />
+                <img src="../../../images/u2fkey.jpg" alt="" class="img-rounded img-responsive" />
             </div>
         </div>
         <div class="list">