nginx: generate certificate on reload

The nginx service would generate a self-certificate upon restart (if
there's not already an existing certificate), but not upon reload.
Enable this for reload as well : the phosphor certificate management app
requires services that want to generate self-signed certificates to do
it upon reload (if reload is supported).

(From meta-ibm rev: bbcf9e563c1a1215434c89fc1cc626a7b3d7fdb6)

Change-Id: Ib3625f256fbae1721e4a9f8ac318287a2b6c03fd
Signed-off-by: Deepak Kodihalli <dkodihal@in.ibm.com>
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/meta-ibm/recipes-httpd/nginx/files/nginx.service b/meta-ibm/recipes-httpd/nginx/files/nginx.service
index 3f9dd3d..a502026 100644
--- a/meta-ibm/recipes-httpd/nginx/files/nginx.service
+++ b/meta-ibm/recipes-httpd/nginx/files/nginx.service
@@ -9,7 +9,7 @@
 ExecStartPre=-/usr/bin/env mkdir /var/volatile/nginx/
 ExecStartPre=/usr/bin/env nginx -t -p /var/volatile/nginx
 ExecStart=/usr/bin/env nginx -p /var/volatile/nginx
-ExecReload=/usr/bin/env kill -s HUP $MAINPID
+ExecReload=/usr/bin/env gen-cert.sh ; /usr/bin/env kill -s HUP $MAINPID
 ExecStop=/usr/bin/env kill -s QUIT $MAINPID
 PrivateTmp=true
 # First time on system takes longer for initial setup so