patch 8.0.0937: user highlight groups not adjusted for terminal

Problem:    User highlight groups are not adjusted for StatusLineTerm.
Solution:   Combine attributes like for StatusLineNC.
diff --git a/src/globals.h b/src/globals.h
index 8fb1205..5c2f3f1 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -362,6 +362,9 @@
 EXTERN int	highlight_user[9];		/* User[1-9] attributes */
 # ifdef FEAT_STL_OPT
 EXTERN int	highlight_stlnc[9];		/* On top of user */
+#  ifdef FEAT_TERMINAL
+EXTERN int	highlight_stlterm[9];		/* On top of user */
+#  endif
 # endif
 #endif
 #ifdef FEAT_GUI