remove scl editor submodule

Author: Sergio Alvarenga

.gitmodules

@@ -6,7 +6,3 @@
 	path = packages/external-plugins/oscd-plugins
 	url = https://github.com/sprinteins/oscd-plugins
 	branch = gh-pages
-[submodule "packages/external-plugins/scl-editor"]
-	path = packages/external-plugins/scl-editor
-	url = https://github.com/danyill/scl-editor
-	branch = gh-pages