dnsmasq: Fix dhcp-boot, dhcp-reply-delay and pxe-prompt regressions

The above options were incorrectly changed to required tags.  Make them
optional again.

Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>

package/network/services/dnsmasq/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=dnsmasq
 PKG_VERSION:=2.80
-PKG_RELEASE:=4
+PKG_RELEASE:=5
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
 PKG_SOURCE_URL:=http://thekelleys.org.uk/dnsmasq

package/network/services/dnsmasq/patches/0014-option-dhcp-boot-dhcp-reply-delay-tag-fixes.patch

@@ -0,0 +1,40 @@
+From 668b45c29c38d440c8fce4bc994c56910adc3919 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Petr=20Men=C5=A1=C3=ADk?= <pemensik@redhat.com>
+Date: Fri, 14 Dec 2018 17:03:08 +0100
+Subject: [PATCH] Fix required tags in few places
+
+Some locations were incorrectly changed to require always tags, else
+dnsmasq will not start. Fix dhcp-boot, dhcp-reply-delay and pxe-prompt.
+---
+ src/option.c | 6 +++---
+ 1 file changed, 3 insertions(+), 3 deletions(-)
+
+--- a/src/option.c
++++ b/src/option.c
+@@ -3434,7 +3434,7 @@ static int one_opt(int option, char *arg
+       {
+ 	struct dhcp_netid *id = dhcp_tags(&arg);
+ 	
+-	if (!id)
++	if (!arg)
+ 	  {
+ 	    ret_err(gen_err);
+ 	  }
+@@ -3485,7 +3485,7 @@ static int one_opt(int option, char *arg
+       {
+ 	struct dhcp_netid *id = dhcp_tags(&arg);
+ 	
+-	if (!id)
++	if (!arg)
+ 	  {
+ 	    ret_err(gen_err);
+ 	  }
+@@ -3515,7 +3515,7 @@ static int one_opt(int option, char *arg
+ 	 new->opt = 10; /* PXE_MENU_PROMPT */
+ 	 new->netid = dhcp_tags(&arg);
+ 	 
+-	 if (!new->netid)
++	 if (!arg)
+ 	   {
+ 	     dhcp_opt_free(new);
+ 	     ret_err(gen_err);