Add space to BlacklistedError phrase list

src/lib/errors/BlacklistedError.ts

@@ -5,6 +5,6 @@ import {BaseError} from "./BaseError";
  */
 export class BlacklistedError extends BaseError {
     constructor(public phrases: string[], field: string = "input") {
-        super(`The ${field} contains the blacklisted words: ${phrases.join(",")}`);
+        super(`The ${field} contains the blacklisted words: ${phrases.join(", ")}`);
     }
 }