patch 8.0.0872: no mouse scroll with a terminal window

Problem:    Using mouse scroll while a terminal window has focus and the mouse
            pointer is on another window does not work.  Same for focus in a
            non-terminal window ahd the mouse pointer is over a terminal
            window.
Solution:   Send the scroll action to the right window.
diff --git a/src/proto/terminal.pro b/src/proto/terminal.pro
index 157b6aa..b6c27ed 100644
--- a/src/proto/terminal.pro
+++ b/src/proto/terminal.pro
@@ -5,6 +5,7 @@
 int term_job_running(term_T *term);
 int term_in_terminal_mode(void);
 void term_leave_terminal_mode(void);
+int send_keys_to_term(term_T *term, int c, int typed);
 int term_use_loop(void);
 int terminal_loop(void);
 void term_job_ended(job_T *job);