Minor fixes in v-change-sys-webmail

Fix incorrect options comment
Check for webmail.inc before modifying it

Author: Kristan Kenney

bin/v-change-sys-webmail

@@ -1,6 +1,6 @@
 #!/bin/bash
 # info: change webmail alias url
-# options: USER DOMAIN
+# options: WEBMAIL
 #
 # This function changes the webmail url in apache2 or nginx configuration.
 
@@ -34,6 +34,7 @@ done
 # Set new webmail alias
 $BIN/v-change-sys-config-value 'WEBMAIL_ALIAS' $NEW_ALIAS
 
+# Add new webmail configuration
 for user in `ls /usr/local/hestia/data/users/`; do
     for domain in $($BIN/v-list-mail-domains $user plain |cut -f 1); do
         $BIN/v-add-sys-webmail $user $domain
@@ -44,8 +45,9 @@ done
 if [ "$WEB_SYSTEM" = "apache2" ]; then
     sed -i "s|Alias \/$OLD_ALIAS|Alias \/$NEW_ALIAS|gI" /etc/apache2/conf.d/roundcube.conf
 fi
-
-sed -i "s|location \/$OLD_ALIAS|location \/$NEW_ALIAS|gI" /etc/nginx/conf.d/webmail.inc
+if [ -e "/etc/nginx/conf.d/webmail.inc" ]; then
+    sed -i "s|location \/$OLD_ALIAS|location \/$NEW_ALIAS|gI" /etc/nginx/conf.d/webmail.inc
+fi
 
 #----------------------------------------------------------#
 #                       Hestia                             #