fix tags in galaxy.yml - no dashes allowed

Signed-off-by: rndmh3ro <[email protected]>

Author: rndmh3ro

galaxy.yml

@@ -17,10 +17,10 @@ tags:
   - nginx
   - mysql
   - openssh
-  - ansible-apache-hardening
-  - mysql-hardening
-  - nginx-hardening
-  - os-hardening
+  - apache_hardening
+  - mysql_hardening
+  - nginx_hardening
+  - os_hardening
   - ssh-hardening
 dependencies:
   ansible.posix: '>=1.0.0'