patch 9.0.0770: quickfix commands may keep memory allocated

Problem:    Quickfix commands may keep memory allocated.
Solution:   Free memory when it's a bit much. (Yegappan Lakshmanan,
            closes #11379)
diff --git a/src/version.c b/src/version.c
index 73b397c..e9cacd5 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    770,
+/**/
     769,
 /**/
     768,