patch 8.0.0912: cannot run a job in a hidden terminal

Problem:    Cannot run a job in a hidden terminal.
Solution:   Add option "hidden" and ++hidden.
diff --git a/src/fileio.c b/src/fileio.c
index 750c08f..f54fb84 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -6890,6 +6890,9 @@
 #ifdef FEAT_NETBEANS_INTG
 	    || isNetbeansBuffer(buf)
 #endif
+#ifdef FEAT_TERMINAL
+	    || buf->b_term != NULL
+#endif
 	    )
 	return 0;