Update dependency NHibernate to v5.4.9 [SECURITY] (#702)

+semver:feature

Author: renovate[bot]

src/FluentNHibernate/FluentNHibernate.csproj

@@ -15,7 +15,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="NHibernate" Version="5.4.8" />
+    <PackageReference Include="NHibernate" Version="5.4.9" />
   </ItemGroup>
 
   <ItemGroup>