patch 8.2.2003: build error with +conceal but without +popupwin

Problem:    Build error with +conceal but without +popupwin.
Solution:   Add #ifdef. (Tom Ryder, closes #7316)
diff --git a/src/version.c b/src/version.c
index 7f49967..a34e9bf 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2003,
+/**/
     2002,
 /**/
     2001,