patch 8.0.0784: job of terminal may be garbage collected

Problem:    Job of terminal may be garbage collected.
Solution:   Set copyID on job in terminal. (Ozaki Kiichi)
diff --git a/src/proto/terminal.pro b/src/proto/terminal.pro
index d7d1538..ac0beb5 100644
--- a/src/proto/terminal.pro
+++ b/src/proto/terminal.pro
@@ -6,4 +6,5 @@
 void term_job_ended(job_T *job);
 void term_update_window(win_T *wp);
 char_u *term_get_status_text(term_T *term);
+int set_ref_in_term(int copyID);
 /* vim: set ft=c : */