(#850) Fix: Improve check for get valid steamid

[Rushaway]

Description

After #850 i discovered another way to broke the code by inserting an invalid steam_id format in dabtase

Motivation and Context

That broke the page display :<

How Has This Been Tested?

Method used:
Check the first 3 characters after STEAM_ to see if it contains ID_ for see if it's not a valid STEAMID format.
Both of these 2 value return GetClientAuthId as true :

• STEAM_ID_STOP_IGNORING_RETVALS
• STEAM_ID_PENDING

Tested and approved ☑️

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.