Removed unnecessary check 'installed' system value' call.
Removed unnecessary check 'installed' system value' call.

OC_Utils::checkServer makes an unnecessary call to $config->getSystemValue('installed', false), which replicates the call made immediately before it during the call to needUpgrade.
pixelipo/server,michaelletzgus/nextcloud-server,jbicha/server,Ardinis/server,pmattern/server,owncloud/core,owncloud/core,sharidas/core,pollopolea/core,cernbox/core,cernbox/core,xx621998xx/server,sharidas/core,pmattern/server,bluelml/core,endsguy/server,bluelml/core,pixelipo/server,pmattern/server,andreas-p/nextcloud-server,jbicha/server,michaelletzgus/nextcloud-server,andreas-p/nextcloud-server,IljaN/core,cernbox/core,endsguy/server,michaelletzgus/nextcloud-server,pollopolea/core,bluelml/core,whitekiba/server,IljaN/core,michaelletzgus/nextcloud-server,Ardinis/server,sharidas/core,xx621998xx/server,endsguy/server,sharidas/core,pixelipo/server,owncloud/core,xx621998xx/server,phil-davis/core,pmattern/server,xx621998xx/server,sharidas/core,cernbox/core,owncloud/core,IljaN/core,jbicha/server,cernbox/core,bluelml/core,pollopolea/core,nextcloud/server,nextcloud/server,Ardinis/server,whitekiba/server,bluelml/core,IljaN/core,pixelipo/server,whitekiba/server,Ardinis/server,Ardinis/server,jbicha/server,jbicha/server,nextcloud/server,andreas-p/nextcloud-server,whitekiba/server,nextcloud/server,pmattern/server,pollopolea/core,andreas-p/nextcloud-server,endsguy/server,pixelipo/server,pollopolea/core,IljaN/core,endsguy/server,owncloud/core,whitekiba/server,andreas-p/nextcloud-server,xx621998xx/server