patch 8.2.0573: using :version twice leaks memory

Problem:    using :version twice leaks memory
Solution:   Only initialize variables once. (Dominique Pelle, closes #5917)
diff --git a/src/testdir/test_alot.vim b/src/testdir/test_alot.vim
index 375213c..83f2c19 100644
--- a/src/testdir/test_alot.vim
+++ b/src/testdir/test_alot.vim
@@ -32,4 +32,5 @@
 source test_tagcase.vim
 source test_tagfunc.vim
 source test_unlet.vim
+source test_version.vim
 source test_wnext.vim