THe warning tells you the function exists, but that you have supplied a bad file address. My guess is that it's a typo in your code:
Warning: file_get_contents(http://url)
This sort of error is typically where your code says something like:
$result=file_get_contents("http://url");
and you left the dollar sign off -- you MEANT to say:
$result=file_get_contents("http://$url");
or something similar.
Since you are calling the function with an array element as the parameter, you will have to look for how you set that value of that element. Probably, some place in your code,,m instead you set a value like:
$url= "www.yourwebsitehere.com"
but instead of setting the value of the array
$_FILES['fisier1']['name']=$url;
you instead say:
$_FILES['fisier1']['name']=url;
or something similar.