Update format of version declaration

Shellfu v0.10.4+ will use the newer format.  This does not justify
hard dependency change, as no known functional components rely on the
version; only thing that uses it is sfdoc to display module version in
man page footer.

src/saturnin.sh.skel

@@ -652,4 +652,4 @@ _saturnin__nl2colon() {
     done
 }
 
-#shellfu module-version: __MKIT_PROJ_VERSION__
+#shellfu module-version=__MKIT_PROJ_VERSION__