uclient: update to latest git HEAD

uclient: update to latest git HEAD

f2573da uclient-fetch: use package name pattern in message for missing SSL library
9fd8070 uclient-fetch: Check for nullpointer returned by uclient_get_url_filename
f41ff60 uclient-http: basic auth: Handle memory allocation failure
a73b23b uclient-http: auth digest: Handle multiple possible memory allocation failures
66fb58d uclient-http: Handle memory allocation failure
2ac991b uclient: Handle memory allocation failure for url
63beea4 uclient-http: Implement error handling for header-sending
eb850df uclient-utils: Handle memory allocation failure for url file name
ae1c656 uclient-http: Close ustream file handle only if allocated

Signed-off-by: Jo-Philipp Wich <jo@mein.io>
(backported from commit e44162ffca448d024fe023944df702c9d3f6b586)