patch 8.2.2375: test for RGB color skipped in the terminal

Problem:    Test for RGB color skipped in the terminal.
Solution:   Run the GUI if possible.
diff --git a/src/version.c b/src/version.c
index 98f120b..452fa2d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2375,
+/**/
     2374,
 /**/
     2373,