patch 8.1.0773: not all crypt code is tested

Problem:    Not all crypt code is tested.
Solution:   Disable unused crypt code.  Add more test coverage.
diff --git a/src/version.c b/src/version.c
index 84d5831..ac81d2e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -792,6 +792,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    773,
+/**/
     772,
 /**/
     771,