runner: avoid reloading config file if  path never changes (#3411)
runner: avoid reloading config file if  path never changes (#3411)


JoshuaKGoldberg/tslint,andy-ms/tslint,andy-ms/tslint,mprobst/tslint,palantir/tslint,JoshuaKGoldberg/tslint,JoshuaKGoldberg/tslint,andy-hanson/tslint,andy-hanson/tslint,andy-hanson/tslint,andy-ms/tslint,mprobst/tslint,mprobst/tslint,palantir/tslint,palantir/tslint