patch 8.1.0748: using sprintf() instead of semsg()

Problem:    Using sprintf() instead of semsg().
Solution:   Use semsg().  Fix bug with E888. (Ozaki Kiichi, closes #3801)
diff --git a/src/version.c b/src/version.c
index c6b9d5f..e01d1c7 100644
--- a/src/version.c
+++ b/src/version.c
@@ -796,6 +796,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    748,
+/**/
     747,
 /**/
     746,