REGTEST: add missing lua requirements on server removal test

The test that removes server via CLI is using LUA to check that servers
referenced in a LUA script cannot be removed. This requires LUA support
to be built in haproxy.

Split the test and create a new one containing only the LUA relevant
test. Mark it as LUA dependant.
diff --git a/reg-tests/server/cli_delete_server.vtc b/reg-tests/server/cli_delete_server.vtc
index d752d6f..7487fc7 100644
--- a/reg-tests/server/cli_delete_server.vtc
+++ b/reg-tests/server/cli_delete_server.vtc
@@ -7,15 +7,7 @@
 
 #REQUIRE_VERSION=2.4
 
-server s1 {
-	rxreq
-	txresp
-} -start
-
 haproxy h1 -conf {
-	global
-		lua-load ${testdir}/get_srv_stats.lua
-
 	defaults
 		mode http
 		timeout connect 1s
@@ -28,13 +20,11 @@
 		default_backend test
 
 	backend test
-		http-request add-header s4-stats %[lua.get_srv_stats(s4)]
 		use-server s3 unless { always_false }
 		server s1 ${s1_addr}:${s1_port}          # referenced in ACL
 		server s2 ${s1_addr}:${s1_port} check    # referenced in track
 		server s3 ${s1_addr}:${s1_port} track s2 # referenced in use-server
-		server s4 ${s1_addr}:${s1_port}          # referenced in lua script
-		server s5 ${s1_addr}:${s1_port}          # removable server
+		server s4 ${s1_addr}:${s1_port}          # removable server
 } -start
 
 haproxy h1 -cli {
@@ -61,26 +51,15 @@
 	# tracked server
 	send "experimental-mode on; del server test/s3"
 	expect ~ "This server cannot be removed at runtime due to other configuration elements pointing to it."
-}
-
-# make a request to force the execution of the lua script which references a
-# server
-client c1 -connect ${h1_feS_sock} {
-	txreq
-	rxresp
-} -run
 
-haproxy h1 -cli {
+	# server in running mode
 	send "experimental-mode on; del server test/s4"
-	expect ~ "This server cannot be removed at runtime due to other configuration elements pointing to it."
-
-	send "experimental-mode on; del server test/s5"
 	expect ~ "Only servers in maintenance mode can be deleted."
 
-	send "disable server test/s5"
+	send "disable server test/s4"
 	expect ~ ".*"
 
 	# valid command
-	send "experimental-mode on; del server test/s5"
+	send "experimental-mode on; del server test/s4"
 	expect ~ "Server deleted."
 }
diff --git a/reg-tests/server/cli_delete_server_lua.vtc b/reg-tests/server/cli_delete_server_lua.vtc
new file mode 100644
index 0000000..ab4200f
--- /dev/null
+++ b/reg-tests/server/cli_delete_server_lua.vtc
@@ -0,0 +1,44 @@
+# This script is to check that servers that are referenced by a lua script
+# cannot be removed at runtime.
+varnishtest "Delete lua server via cli"
+
+feature ignore_unknown_macro
+
+#REQUIRE_VERSION=2.5
+#REQUIRE_OPTIONS=LUA
+
+server s1 {
+	rxreq
+	txresp
+} -start
+
+haproxy h1 -conf {
+	global
+		lua-load ${testdir}/get_srv_stats.lua
+
+	defaults
+		mode http
+		timeout connect 1s
+		timeout client  1s
+		timeout server  1s
+
+	frontend fe
+		bind "fd@${feS}"
+		default_backend test
+
+	backend test
+		http-request add-header s1-stats %[lua.get_srv_stats(s1)]
+		server s1 ${s1_addr}:${s1_port}          # referenced in lua script
+} -start
+
+# make a request to force the execution of the lua script which references a
+# server
+client c1 -connect ${h1_feS_sock} {
+	txreq
+	rxresp
+} -run
+
+haproxy h1 -cli {
+	send "experimental-mode on; del server test/s1"
+	expect ~ "This server cannot be removed at runtime due to other configuration elements pointing to it."
+}