patch 8.1.0949: MS-windows defines GUI macros different than other systems

Problem:    MS-windows defines GUI macros different than other systems.
Solution:   Swap FEAT_GUI and FEAT_GUI_MSWIN. (Hirohito Higashi, closes #3996)
diff --git a/src/vim.rc b/src/vim.rc
index c3d3f5f..51c3b7b 100644
--- a/src/vim.rc
+++ b/src/vim.rc
@@ -23,7 +23,7 @@
 //
 IDR_VIM		ICON "vim.ico"
 
-#ifdef FEAT_GUI
+#ifdef FEAT_GUI_MSWIN
 IDR_VIM_ERROR	ICON "vim_error.ico"
 IDR_VIM_ALERT	ICON "vim_alert.ico"
 IDR_VIM_INFO	ICON "vim_info.ico"
@@ -46,7 +46,7 @@
 #endif
 
 CREATEPROCESS_MANIFEST_RESOURCE_ID RT_MANIFEST "gvim.exe.mnf"
-#endif // FEAT_GUI
+#endif // FEAT_GUI_MSWIN
 
 //
 // Type Library