Fix grammar

creategroup

@@ -13,7 +13,7 @@ fi
 cn="$1"
 
 if group_exists $cn; then
-    echo "Group $cn already exist." 
+    echo "Group $cn already exists." 
     exit 1
 fi
 

createperson

@@ -31,7 +31,7 @@ done
 pw=$(/usr/sbin/slappasswd -s "salut$uid")
 
 if user_exists $uid; then
-    echo "User $uid already exist." 
+    echo "User $uid already exists." 
     exit 1
 fi