Restore setting of GOVERSIONOPTION

Accidentally removed in last commit.
diff --git a/configure.ac b/configure.ac
index a38e97d..73c38a7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2390,6 +2390,7 @@
   GOVERSIONOPTION=
 
   if test -n "$GO" ; then
+    GOVERSIONOPTION=version
     AC_MSG_CHECKING([whether go version is too old])
     case $go_version in
     go1.[012345]*)