I hope that the log is useful to understand the problem, if not please be patient and help me to use correctly the strace command that you tell me before
In your trace I see
28806 stat64("/etc/ssl/certs/157753a5.0", <unfinished ...>
...
28806 <... stat64 resumed> 0xb37ce5f8) = -1 ENOENT (No such file or directory)
This means your box lacks CA to check our certificate. Please update SSL CA certs packages.