Update fragment_authentication_server.xml

Don't permit uppercase characters...

app/src/main/res/layout/fragment_authentication_server.xml

@@ -32,7 +32,7 @@
         android:cursorVisible="false"
         android:hint="@string/default_server"
         android:imeOptions="actionDone"
-        android:digits="0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ.-/:"
+        android:digits="0123456789abcdefghijklmnopqrstuvwxyz.-/:"
         android:inputType="textUri"
         android:paddingEnd="0dp"
         android:paddingStart="0dp" />
@@ -52,4 +52,4 @@
         android:layout_alignParentBottom="true"
         android:text="@string/action_connect" />
 
-</RelativeLayout>
\ No newline at end of file
+</RelativeLayout>