Revert "Made Conditional references in csproj file"

This reverts commit e24eb5fc782ec08631638b0ff20494231fd3e08d.
Revert "Add the DebugGTK3 type of configuration to sln"

This reverts commit 6f529d73e4c1c626a8aed079728b61e0c51dc432.
Revert "Add Conditional check for GTK3"

This reverts commit 2f0c1360b78e379555331a914d8471f8864e1d50.