Update seafile-controller.c

Now short_opts correctly contains upper case L instead of lower case l (option for setting log file path)
Segfault removed

In case the log file is not available (wrong path, no permissions, etc..) the custom glib handler functions are called anyway and try to write to nullptr in seafile_log and ccnet_log via logfp which results in a segmentation fault. Now the messages are sent to stdout.
Merge pull request #838 from dbruenig/master

Removed typo in seafile-controller.c, removed segfault in common/log.c