patch 8.2.0870: MS-Windows: Control keys don't work in the GUI

Problem:    MS-Windows: Control keys don't work in the GUI.
Solution:   Don't set seenModifyOtherKeys for now. (Yasuhiro Matsumoto,
            closes #6175)
diff --git a/src/gui.c b/src/gui.c
index 3df9921..dc408bb 100644
--- a/src/gui.c
+++ b/src/gui.c
@@ -803,8 +803,13 @@
 	if (!p_beval)
 	    gui_mch_disable_beval_area(balloonEval);
 #endif
+
+#ifndef FEAT_GUI_MSWIN
 	// In the GUI modifiers are prepended to keys.
+	// Don't do this for MS-Windows yet, it sends CTRL-K without the
+	// modifier.
 	seenModifyOtherKeys = TRUE;
+#endif
 
 #if defined(FEAT_XIM) && defined(FEAT_GUI_GTK)
 	if (!im_xim_isvalid_imactivate())