patch 9.0.1120: tex filetype detection not sufficiently tested

Problem:    Tex filetype detection not sufficiently tested.
Solution:   Add more test cases for "tex" detection. (Jonas Strittmatter,
            closes #11765)
diff --git a/src/version.c b/src/version.c
index 92c70ea..230db82 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1120,
+/**/
     1119,
 /**/
     1118,