patch 8.2.2293: build failure with Motif

Problem:    Build failure with Motif. (Tony Mechelynck)
Solution:   Use empty_option instead of empty_options.
diff --git a/src/version.c b/src/version.c
index 6b96628..258c7d9 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2293,
+/**/
     2292,
 /**/
     2291,