Ignoring [._]*.sw[a-p] instead of *.s[a-w][a-z]

The old pattern was too broad and was making VIM ignore Scheme (*.scm) files.
Now it only matches files that start with . or _.

Global/vim.gitignore

@@ -1,5 +1,5 @@
-.*.s[a-w][a-z]
-.s[a-w][a-z]
+[._]*.s[a-w][a-z]
+[._]s[a-w][a-z]
 *.un~
 Session.vim
 .netrwhist