patch 8.1.1938: may crash when out of memory

Problem:    May crash when out of memory.
Solution:   Initialize v_type to VAR_UNKNOWN. (Dominique Pelle, closes #4871)
diff --git a/src/version.c b/src/version.c
index c6bf6c5..96e0b40 100644
--- a/src/version.c
+++ b/src/version.c
@@ -762,6 +762,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1938,
+/**/
     1937,
 /**/
     1936,