Fix Database#remove_cached_schema on PostgreSQL
Fix Database#remove_cached_schema on PostgreSQL

Bitten by ruby's reassign method argument variable and call super
without arguments wart.

pfarrell/sequel,t-morgan/sequel,t-morgan/sequel,knut2/sequel,seeARMS/sequel,gferguson-gd/sequel,nicohvi/sequel,dennis-d/custom_sequel,offshore-safety/sequel,uhoh-itsmaciek/sequel,nicohvi/sequel,nju520/sequel,reubano/sequel,beni55/sequel,yazshel/sequel,chef/sequel,reubano/sequel,offshore-safety/sequel,gferguson-gd/sequel,beni55/sequel,mpalmer/sequel,Marketcircle/sequel,mpalmer/sequel,dennis-d/custom_sequel,yazshel/sequel,davidbegin/sequel,bigfix/sequel,knut2/sequel,freshpay/sequel,freshpay/sequel,seeARMS/sequel,offshore-safety/sequel,nju520/sequel,davidbegin/sequel,pfarrell/sequel,uhoh-itsmaciek/sequel