patch 8.0.1810: buffer of a terminal only updated in Terminal-Normal mode

Problem:    Buffer of a terminal only updated in Terminal-Normal mode.
Solution:   Copy the terminal window content to the buffer when in
            Terminal-Job mode.
diff --git a/src/proto/terminal.pro b/src/proto/terminal.pro
index f97f025..93c6ab5 100644
--- a/src/proto/terminal.pro
+++ b/src/proto/terminal.pro
@@ -9,6 +9,7 @@
 int term_job_running(term_T *term);
 int term_none_open(term_T *term);
 int term_try_stop_job(buf_T *buf);
+int term_check_timers(int next_due_arg, proftime_T *now);
 int term_in_normal_mode(void);
 void term_enter_job_mode(void);
 int send_keys_to_term(term_T *term, int c, int typed);