reset host when using login via QR/link

Signed-off-by: tobiasKaminsky <tobias@kaminsky.me>

src/main/java/com/owncloud/android/authentication/AuthenticatorActivity.java

@@ -505,6 +505,7 @@ public class AuthenticatorActivity extends AccountAuthenticatorActivity
 
         if (loginUrlInfo != null) {
             try {
+                mHostUrlInput.setText("");
                 mServerInfo.mBaseUrl = AuthenticatorUrlUtils.normalizeUrlSuffix(loginUrlInfo.serverAddress);
                 webViewUser = loginUrlInfo.username;
                 webViewPassword = loginUrlInfo.password;