Fix logging of enabled middlewares
Fix logging of enabled middlewares

Wrong middlewares list was being pretty-printed
(introduced in #1263)

wujuguang/scrapy,finfish/scrapy,pawelmhm/scrapy,taito/scrapy,w495/scrapy,ArturGaspar/scrapy,redapple/scrapy,rootAvish/scrapy,scrapy/scrapy,Parlin-Galanodel/scrapy,rklabs/scrapy,scrapy/scrapy,shaform/scrapy,dangra/scrapy,carlosp420/scrapy,YeelerG/scrapy,elacuesta/scrapy,arush0311/scrapy,eLRuLL/scrapy,dangra/scrapy,kmike/scrapy,darkrho/scrapy-scrapy,wenyu1001/scrapy,finfish/scrapy,dangra/scrapy,dracony/scrapy,pablohoffman/scrapy,taito/scrapy,GregoryVigoTorres/scrapy,YeelerG/scrapy,shaform/scrapy,dracony/scrapy,pablohoffman/scrapy,cyberplant/scrapy,foromer4/scrapy,pablohoffman/scrapy,elacuesta/scrapy,crasker/scrapy,Parlin-Galanodel/scrapy,kmike/scrapy,ssteo/scrapy,rolando-contrib/scrapy,ssteo/scrapy,GregoryVigoTorres/scrapy,w495/scrapy,crasker/scrapy,kmike/scrapy,starrify/scrapy,redapple/scrapy,pawelmhm/scrapy,ArturGaspar/scrapy,Parlin-Galanodel/scrapy,dracony/scrapy,umrashrf/scrapy,umrashrf/scrapy,eLRuLL/scrapy,darkrho/scrapy-scrapy,rootAvish/scrapy,rolando/scrapy,rolando/scrapy,arush0311/scrapy,redapple/scrapy,crasker/scrapy,barraponto/scrapy,carlosp420/scrapy,ArturGaspar/scrapy,rolando/scrapy,rklabs/scrapy,wujuguang/scrapy,YeelerG/scrapy,wujuguang/scrapy,rolando-contrib/scrapy,Ryezhang/scrapy,rolando-contrib/scrapy,rklabs/scrapy,starrify/scrapy,arush0311/scrapy,shaform/scrapy,eLRuLL/scrapy,barraponto/scrapy,carlosp420/scrapy,rootAvish/scrapy,jc0n/scrapy,Ryezhang/scrapy,jc0n/scrapy,wenyu1001/scrapy,foromer4/scrapy,GregoryVigoTorres/scrapy,pawelmhm/scrapy,scrapy/scrapy,ssteo/scrapy,Ryezhang/scrapy,wenyu1001/scrapy,jc0n/scrapy,taito/scrapy,finfish/scrapy,cyberplant/scrapy,cyberplant/scrapy,darkrho/scrapy-scrapy,elacuesta/scrapy,w495/scrapy,barraponto/scrapy,starrify/scrapy,umrashrf/scrapy,foromer4/scrapy