patch 9.0.0150: error for using #{ in an expression is a bit confusing

Problem:    Error for using #{ in an expression is a bit confusing.
Solution:   Mention that this error is only given for an expression.
            Avoid giving the error more than once. (closes #10855)
diff --git a/src/version.c b/src/version.c
index acecc11..27d269e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -736,6 +736,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    150,
+/**/
     149,
 /**/
     148,