MINOR: cfgparse: Make "peer" lines be parsed as "server" lines.

With this patch "default-server" lines are supported in "peers" sections
to setup the default settings of peers which are from now setup
when parsing both "peer" and "server" lines.

May be backported to 1.5 and newer.
diff --git a/src/peers.c b/src/peers.c
index 4314d58..e580f2c 100644
--- a/src/peers.c
+++ b/src/peers.c
@@ -1930,7 +1930,7 @@
 void peers_setup_frontend(struct proxy *fe)
 {
 	fe->last_change = now.tv_sec;
-	fe->cap = PR_CAP_FE;
+	fe->cap = PR_CAP_FE | PR_CAP_BE;
 	fe->maxconn = 0;
 	fe->conn_retries = CONN_RETRIES;
 	fe->timeout.client = MS_TO_TICKS(5000);