Bug#778672: Still a problem on Debian 9.3

[mat974 at web.de]

Unfortunately, this bug still exists on Debian 9.3, linphone 3.6.1-3.

$ strace -e open,read linphone 
(...)
open("/etc/ssl/certs", O_RDONLY)        = 16
read(16, 0x586d1ec8, 1024)              = -1 EISDIR (Is a directory)
open("", O_RDONLY)                      = -1 ENOENT (No such file or directory)
open("/etc/ssl/certs", O_RDONLY)        = 16
open("/usr/lib/i386-linux-gnu/gdk-pixbuf-2.0/2.10.0/loaders.cache", O_RDONLY|O_LARGEFILE) = 16
(...)

I suppose that using the second code line in coreapi/linphonecore.c for all operating systems would be sufficient:
#ifdef __linux
	sal_set_root_ca(lc->sal, lp_config_get_string(lc->config,"sip","root_ca", "/etc/ssl/certs"));
#else
	sal_set_root_ca(lc->sal, lp_config_get_string(lc->config,"sip","root_ca", ROOT_CA_FILE));
#endif