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/optiondefs.h b/src/optiondefs.h
index 881ec06..8fda8bf 100644
--- a/src/optiondefs.h
+++ b/src/optiondefs.h
@@ -688,7 +688,7 @@
 			    {(char_u *)"menu,preview", (char_u *)0L}
 			    SCTX_INIT},
     {"completepopup", "cpp", P_STRING|P_VI_DEF|P_COMMA|P_NODUP,
-#if defined(FEAT_TEXT_PROP) && defined(FEAT_QUICKFIX)
+#if defined(FEAT_PROP_POPUP) && defined(FEAT_QUICKFIX)
 			    (char_u *)&p_cpp, PV_NONE,
 			    {(char_u *)"", (char_u *)0L}
 #else
@@ -1897,7 +1897,7 @@
 #endif
 			    {(char_u *)12L, (char_u *)0L} SCTX_INIT},
     {"previewpopup", "pvp", P_STRING|P_VI_DEF|P_COMMA|P_NODUP,
-#ifdef FEAT_TEXT_PROP
+#ifdef FEAT_PROP_POPUP
 			    (char_u *)&p_pvp, PV_NONE,
 			    {(char_u *)"", (char_u *)0L}
 #else