patch 8.2.4008: error messages are spread out

Problem:    Error messages are spread out.
Solution:   Move more error messages to errors.h.
diff --git a/src/quickfix.c b/src/quickfix.c
index f7d35f8..9021029 100644
--- a/src/quickfix.c
+++ b/src/quickfix.c
@@ -7978,7 +7978,7 @@
 	return OK;
     }
 
-    emsg(_("E777: String or List expected"));
+    emsg(_(e_string_or_list_expected));
     return FAIL;
 }