patch 8.2.0788: memory leak in libvterm

Problem:    Memory leak in libvterm.
Solution:   free tmpbuffer.
diff --git a/src/version.c b/src/version.c
index abdb68a..4dcae55 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    788,
+/**/
     787,
 /**/
     786,