[FIX] Don't preload company logo of the wrong company

How to reproduce:
Using Firefox 31.0, log in as a user with a different company than user with uid 1. The company logo of the company of this admin user is displayed until the user performs his first action (i.e. click).

Analysis:
The webclient preloads the company logo when showing the login screen with uid 1.

Patch:
Don't preload the company logo.