fix(validation.js): Remove ES lint waiver

#668

Author: Robert Gregg

lib/editor/util/validation.js

@@ -25,7 +25,6 @@ export function doesNotExist (value: any): boolean {
  * Returns false if the value is ok.
  * Returns an EditorValidationIssue object if the value is not ok.
  */
-// eslint-disable-next-line complexity
 export function validate (
   field: GtfsSpecField,
   value: any,