Fix possible thread-safety issue on non-GVL ruby implementations in single_table_inheritance plugin
Fix possible thread-safety issue on non-GVL ruby implementations in single_table_inheritance plugin

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