BUILD: ssl: fix typo causing a build failure in the multicert patch

I just noticed that SSL wouldn't build anymore since this afternoon's patch :

src/ssl_sock.c: In function 'ssl_sock_load_multi_cert':
src/ssl_sock.c:1982:26: warning: left-hand operand of comma expression has no effect [-Wunused-value]
    for (i = 0; i < fcount, i++)
                          ^
src/ssl_sock.c:1982:31: error: expected ';' before ')' token
    for (i = 0; i < fcount, i++)
                               ^
Makefile:791: recipe for target 'src/ssl_sock.o' failed
make: *** [src/ssl_sock.o] Error 1
1 file changed