Update apps/roundcube/src/INSTALL
Update apps/roundcube/src/INSTALL

include information about needed "Bookmarks" plugin
hypery2k/owncloud,Fmstrat/owncloud,hypery2k/owncloud,amirshaikh49/owncloud,lahmizzar/owncloud,mhtranbn/owncloud,Fmstrat/owncloud,mhtranbn/owncloud,lahmizzar/owncloud,lahmizzar/owncloud,Fmstrat/owncloud,amirshaikh49/owncloud,hypery2k/owncloud,lahmizzar/owncloud,mhtranbn/owncloud,Fmstrat/owncloud,amirshaikh49/owncloud,mhtranbn/owncloud,Fmstrat/owncloud,amirshaikh49/owncloud,hypery2k/owncloud,lahmizzar/owncloud,lahmizzar/owncloud,amirshaikh49/owncloud,amirshaikh49/owncloud,Fmstrat/owncloud,hypery2k/owncloud,mhtranbn/owncloud,hypery2k/owncloud,mhtranbn/owncloud