[bugfix] chunked transfer http encoding

[Valentin Dudouyt]

LWP hangs when POSTing on server that uses chunked transfer-encoding.
The solution is to prevent reading while file is not uploaded 
completely. Please, take a look on attachment (diff of 
lib/LWP/Protocol/http.pm).

Best Regards,
Valentin.
269a270
> 	my $strobe_read;
302c303
< 	    if (defined($rbits) && $rbits =~ /[^\0]/) {
---
> 	    if (defined($rbits) && $rbits =~ /[^\0]/ && !$strobe_read) {
334a336
> 		$strobe_read = 1;