patch 8.1.1661: cannot build with +textprop but without +balloon_eval

Problem:    Cannot build with +textprop but without +balloon_eval.
Solution:   Adjust #ifdefs. (closes #4645)
diff --git a/src/proto.h b/src/proto.h
index 81023e2..1c37bfa 100644
--- a/src/proto.h
+++ b/src/proto.h
@@ -230,13 +230,14 @@
 #  include "if_ruby.pro"
 # endif
 
-/* Ugly solution for "BalloonEval" not being defined while it's used in some
- * .pro files. */
-# ifdef FEAT_BEVAL
-#  include "beval.pro"
-# else
+// Ugly solution for "BalloonEval" not being defined while it's used in some
+// .pro files.
+# ifndef FEAT_BEVAL
 #  define BalloonEval int
 # endif
+# if defined(FEAT_BEVAL) || defined(FEAT_TEXT_PROP)
+#  include "beval.pro"
+# endif
 
 # ifdef FEAT_NETBEANS_INTG
 #  include "netbeans.pro"