fix colon issue (#532)

Author: Smile Chang

src/schema-routes/schema-routes.ts

@@ -98,7 +98,7 @@ export class SchemaRoutes {
 
     // TODO forbid leading symbols [\]^` in a major release (allowed yet for backwards compatibility)
     const pathParamMatches = (routeName || "").match(
-      /({[\w[\\\]^`][-_.\w]*})|(:[\w[\\\]^`][-_.\w]*:?)/g,
+      /(?<=\/)({[\w[\\\]^`][-_.\w]*})|(?<=\/)(:[\w[\\\]^`][-_.\w]*:?)/g
     );
 
     // used in case when path parameters is not declared in requestInfo.parameters ("in": "path")