CLEANUP: protocol: remove the ->enable_all method

It's not used anymore, now the listeners are enabled from
protocol_enable_all().
diff --git a/include/haproxy/protocol-t.h b/include/haproxy/protocol-t.h
index 9f79015..bf66dc2 100644
--- a/include/haproxy/protocol-t.h
+++ b/include/haproxy/protocol-t.h
@@ -74,8 +74,7 @@
 
 /* This structure contains all information needed to easily handle a protocol.
  * Its primary goal is to ease listeners maintenance. Specifically, the
- * bind() primitive must be used before any fork(), and the enable_all()
- * primitive must be called after the fork() to enable all fds.
+ * bind() primitive must be used before any fork().
  */
 struct protocol {
 	char name[PROTO_NAME_LEN];			/* protocol name, zero-terminated */
@@ -86,7 +85,6 @@
 	int sock_prot;					/* socket protocol, as passed to socket() */
 	void (*accept)(int fd);				/* generic accept function */
 	int (*listen)(struct listener *l, char *errmsg, int errlen); /* start a listener */
-	int (*enable_all)(struct protocol *proto);	/* enable all bound listeners */
 	int (*connect)(struct connection *, int flags); /* connect function if any, see below for flags values */
 	int (*drain)(int fd);                           /* indicates whether we can safely close the fd */
 	int (*pause)(struct listener *l);               /* temporarily pause this listener for a soft restart */
diff --git a/src/proto_sockpair.c b/src/proto_sockpair.c
index 53a4479..c77308f 100644
--- a/src/proto_sockpair.c
+++ b/src/proto_sockpair.c
@@ -68,7 +68,6 @@
 	.accept = &listener_accept,
 	.connect = &sockpair_connect_server,
 	.listen = sockpair_bind_listener,
-	.enable_all = enable_all_listeners,
 	.pause = NULL,
 	.add = sockpair_add_listener,
 	.listeners = LIST_HEAD_INIT(proto_sockpair.listeners),
diff --git a/src/proto_tcp.c b/src/proto_tcp.c
index b9bc97e..4e6d36a 100644
--- a/src/proto_tcp.c
+++ b/src/proto_tcp.c
@@ -59,7 +59,6 @@
 	.accept = &listener_accept,
 	.connect = tcp_connect_server,
 	.listen = tcp_bind_listener,
-	.enable_all = enable_all_listeners,
 	.pause = tcp_pause_listener,
 	.add = tcpv4_add_listener,
 	.listeners = LIST_HEAD_INIT(proto_tcpv4.listeners),
@@ -79,7 +78,6 @@
 	.accept = &listener_accept,
 	.connect = tcp_connect_server,
 	.listen = tcp_bind_listener,
-	.enable_all = enable_all_listeners,
 	.pause = tcp_pause_listener,
 	.add = tcpv6_add_listener,
 	.listeners = LIST_HEAD_INIT(proto_tcpv6.listeners),
diff --git a/src/proto_udp.c b/src/proto_udp.c
index af75cc9..aa2416f 100644
--- a/src/proto_udp.c
+++ b/src/proto_udp.c
@@ -55,7 +55,6 @@
 	.accept = NULL,
 	.connect = NULL,
 	.listen = udp_bind_listener,
-	.enable_all = enable_all_listeners,
 	.pause = udp_pause_listener,
 	.add = udp4_add_listener,
 	.listeners = LIST_HEAD_INIT(proto_udp4.listeners),
@@ -75,7 +74,6 @@
 	.accept = NULL,
 	.connect = NULL,
 	.listen = udp_bind_listener,
-	.enable_all = enable_all_listeners,
 	.pause = udp_pause_listener,
 	.add = udp6_add_listener,
 	.listeners = LIST_HEAD_INIT(proto_udp6.listeners),
diff --git a/src/proto_uxst.c b/src/proto_uxst.c
index 2b1b0c3..96d96b3 100644
--- a/src/proto_uxst.c
+++ b/src/proto_uxst.c
@@ -56,7 +56,6 @@
 	.accept = &listener_accept,
 	.connect = &uxst_connect_server,
 	.listen = uxst_bind_listener,
-	.enable_all = enable_all_listeners,
 	.pause = uxst_pause_listener,
 	.add = uxst_add_listener,
 	.listeners = LIST_HEAD_INIT(proto_unix.listeners),