patch 9.0.0926: Coverity warns for not using return value of dict_add()

Problem:    Coverity warns for not using return value of dict_add().
Solution:   When dict_add() fails then don't call hash_remove().
diff --git a/src/version.c b/src/version.c
index 6ccc704..c9e3a2e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    926,
+/**/
     925,
 /**/
     924,