Replace <PackageLicenseUrl /> with <PackageLicenseExpression />
Replace <PackageLicenseUrl /> with <PackageLicenseExpression />

Closes #1973
fredericDelaporte/nhibernate-core,nhibernate/nhibernate-core,fredericDelaporte/nhibernate-core,hazzik/nhibernate-core,RogerKratz/nhibernate-core,gliljas/nhibernate-core,hazzik/nhibernate-core,gliljas/nhibernate-core,hazzik/nhibernate-core,ngbrown/nhibernate-core,nhibernate/nhibernate-core,RogerKratz/nhibernate-core,gliljas/nhibernate-core,fredericDelaporte/nhibernate-core,RogerKratz/nhibernate-core,RogerKratz/nhibernate-core,nhibernate/nhibernate-core,ngbrown/nhibernate-core,gliljas/nhibernate-core,ngbrown/nhibernate-core,fredericDelaporte/nhibernate-core,nhibernate/nhibernate-core,hazzik/nhibernate-core