Missing default value for SP_RECONNECT_IVL_MAX added

Signed-off-by: Martin Sustrik <sustrik@250bpm.com>
diff --git a/src/core/sock.c b/src/core/sock.c
index 498629d..eaabccc 100644
--- a/src/core/sock.c
+++ b/src/core/sock.c
@@ -51,6 +51,7 @@
     self->sndtimeo = -1;
     self->rcvtimeo = -1;
     self->reconnect_ivl = 100;
+    self->reconnect_ivl_max = 0;
 }
 
 void sp_sock_zombify (struct sp_sock *self)