scrapyd.launcher: make SCRAPY_LOG_FILE and SCRAPY_FEED_URI optional
scrapyd.launcher: make SCRAPY_LOG_FILE and SCRAPY_FEED_URI optional

wujuguang/scrapyd,nyov/scrapyd,CENDARI/scrapyd,CENDARI/scrapyd,dfockler/scrapyd,2014fgq/scrapyd,dfockler/scrapyd,masterPPP/scrapyd,aivarsk/scrapyd,eliasdorneles/scrapyd,nyov/scrapyd,sigma-random/scrapyd,sigma-random/scrapyd,2014fgq/scrapyd,masterPPP/scrapyd,aivarsk/scrapyd,wujuguang/scrapyd,eliasdorneles/scrapyd,scrapy/scrapyd