Fix login form logic

[YaronMiro]

54

[YaronMiro]

@amitaibu Ready for review. Thanks.

[YaronMiro]

@amitaibu Ready for review.

I did some more changes:

• The inputs fields are now disabled after clicking on the login button - You were able to change their values while the request was been made it was weird... ;)
• Login button color is now gray when disabled - make more scene.
• I removed the variable loginText that was holding the "content markup" for the login button and moved all of it to the markup declaration area so know it's more readable and understood.

This is the new video after the changes:

[YaronMiro]

@amitaibu Ready for review.

[amitaibu]

Merged, thanks!