Added a missing poiunt/exclamation mark

ref #39

src/errors/RunnerTeamErrors.ts

@@ -21,7 +21,7 @@ export class RunnerTeamIdsNotMatchingError extends NotAcceptableError {
 	name = "RunnerTeamIdsNotMatchingError"
 
 	@IsString()
-	message = "The ids don't match!! \n And if you wanted to change a runner's id: This isn't allowed"
+	message = "The ids don't match! \n And if you wanted to change a runner's id: This isn't allowed!"
 }
 
 /**