patch 8.1.2371: FEAT_TEXT_PROP is a confusing name

Problem:    FEAT_TEXT_PROP is a confusing name.
Solution:   Use FEAT_PROP_POPUP. (Naruhiko Nishino, closes #5291)
diff --git a/src/globals.h b/src/globals.h
index e96800d..77a42d8 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -95,7 +95,7 @@
  */
 EXTERN short	*TabPageIdxs INIT(= NULL);
 
-#ifdef FEAT_TEXT_PROP
+#ifdef FEAT_PROP_POPUP
 // Array with size Rows x Columns containing zindex of popups.
 EXTERN short	*popup_mask INIT(= NULL);
 EXTERN short	*popup_mask_next INIT(= NULL);
@@ -640,7 +640,7 @@
 EXTERN win_T	*aucmd_win;	// window used in aucmd_prepbuf()
 EXTERN int	aucmd_win_used INIT(= FALSE);	// aucmd_win is being used
 
-#ifdef FEAT_TEXT_PROP
+#ifdef FEAT_PROP_POPUP
 EXTERN win_T    *first_popupwin;		// first global popup window
 EXTERN win_T	*popup_dragwin INIT(= NULL);	// popup window being dragged