fix/replaced dict keys with list

[erv4gen]

Due to the Runtime error in line 70 and 56, replaced .keys() with list() in the for loop

    for bot in st.session_state.active_bots.keys():
RuntimeError: dictionary changed size during iteration 

[cardosofede]

@david-hummingbot @nikspz @rapcmia can we test this behavior? at first sight makes sense

[rapcmia]

• Setup dashboard on source ✅
• Create / Start master_bot_conf successfully
• Start hummingbot broker
  • Stop master_bot_conf, displays not active on dashboard
  • Start master_bot_conf, running ok
• Created instances from latest/development
  • Start the bot and select script, ok
  • Stop the bot and observe dashboard behavior, displays non active containers
  • While containers are running relaunch dashboard, all containers ok
• Run backtests
  • Create, Optimize, Analyze and Deploy ok

[cardosofede]

LGTM!