fix: stop parsing if URL does not have a schema

scripts/dburl-parser.sh

@@ -14,6 +14,10 @@ queryless_url="${DB_URL%%\?*}";
 
 # get URL's schema
 schema="${queryless_url%//*}";
+if test "${schema}" = "${queryless_url}"; then
+    echo >&2 "database URLs must start with schema (i.e.: mysql://)"\
+    && exit 2;
+fi
 schemaless_url=${queryless_url#*//};
 
 # left hand is everything until the first @ (the user part)