patch 8.0.0658: spell test is old style

Problem:    Spell test is old style.
Solution:   Turn the spell test into a new style test (pschuh, closes #1778)
diff --git a/src/version.c b/src/version.c
index 58ae3ae..ab0381c 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    658,
+/**/
     657,
 /**/
     656,