[TF2] Fix demoman shield floating in midair after respawn

[SanyaKor]

Description

There is an old bug where a demoman's shield floats in midair after respawn. The shield is visible through walls and players.

How to reproduce

1. Equip a demoman shield: Chargin' Targe, Splendid Screen, or Tide Turner.
2. Equip a melee weapon whose first-person viewmodel shows the shield alongside it, such as the Eyelander, Nessie's Nine Iron, Scotsman's Skullcutter, Half-Zatoichi, Persian Persuader, or Claidheamh Mor.
3. Killbind with holding that melee weapon, then spectate a player of any class in first person.(spec_mode 4)
4. Respawn while spectating.
5. After respawning (also switch to melee), your shield remains floating where the spectated player was and is visible through walls and players.

Screenshot

Cause

During firstperson spectating, GetViewModel(0) returns the spectated players viewmodel. The demoman's shield model attaches to it. After the demo respawns, the shield remains at that location and floats in the world.

Fix

Use GetViewModel(0, false) when creating the shield model. This returns the demos own viewmodel, so the shield cannot attach to the player being spectated.