patch 8.0.1592: terminal windows in a session are not properly restored

Problem:    Terminal windows in a session are not properly restored.
Solution:   Add "terminal" in 'sessionoptions'.  When possible restore the
            command running in a terminal.
diff --git a/src/evalfunc.c b/src/evalfunc.c
index 9cbdf3f..aa0ec60 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -867,6 +867,7 @@
     {"term_list",	0, 0, f_term_list},
     {"term_scrape",	2, 2, f_term_scrape},
     {"term_sendkeys",	2, 2, f_term_sendkeys},
+    {"term_setrestore",	2, 2, f_term_setrestore},
     {"term_start",	1, 2, f_term_start},
     {"term_wait",	1, 2, f_term_wait},
 #endif