Update FlowSynx.PluginCore to version 1.3.4

Updated the `FlowSynx.PluginCore` package reference in the
`FlowPack.csproj` file from version `1.3.3` to `1.3.4`.

#17

Author: ziagham

src/FlowPack.csproj

@@ -14,7 +14,7 @@
 	</PropertyGroup>
 
 	<ItemGroup>
-	  <PackageReference Include="FlowSynx.PluginCore" Version="1.3.3" />
+	  <PackageReference Include="FlowSynx.PluginCore" Version="1.3.4" />
 	</ItemGroup>
 
 </Project>