[HL2MP] Fix compile error in HL2MP when using GLOWS_ENABLE

[Blixibon]

Description

This pull request fixes a compile error in HL2MP when using the GLOWS_ENABLE preprocessor.

GLOWS_ENABLE enables code that can add glow outline effects on entities. It is used in TF2 by default, but it can be enabled for any SDK project. However, while it can be compiled as-is under base HL2, there is a dependency within an #ifdef TF_CLIENT_DLL in c_team_train_watcher.cpp which prevents it from compiling under HL2MP.

As this dependency (teamplayroundbased_gamerules.h) is not necessarily TF2-specific, this pull request moves the dependency outside of the #ifdef.