patch 9.0.0994: tests for empty prop type name fail

Problem:    Tests for empty prop type name fail.
Solution:   Correct the error number.
diff --git a/src/version.c b/src/version.c
index 9fbed7c..6b4f103 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    994,
+/**/
     993,
 /**/
     992,