Use root as the ansible user

host_vars/las-gethmann.las.kit.edu

-ansible_user: gethmann
+ansible_user: root
 user_account: gethmann
 ip_suffix: -gethmann
 loc: 618

host_vars/las101.las.kit.edu

-ansible_user: gethmann
-ansible_ssh_user: gethmann
+ansible_user: root
+ansible_ssh_user: root
 ansible_remote_user: gethmann
 remote_user: gethmann
 ip_suffix: 101
-loc: 620
-os: Fedora 24
+loc: 612
+os: Fedora 28

host_vars/las113.las.kit.edu

-ansible_user: gethmann
+ansible_user: root
 user_account: gethmann
 ip_suffix: 113
 loc: 618

host_vars/las115.las.kit.edu

-ansible_user: gethmann
+ansible_user: root
 user_account: ning
 ip_suffix: 115
 loc: 619

host_vars/las117.las.kit.edu

-ansible_user: gethmann
+ansible_user: root
 user_account: damminsek
 ip_suffix: 117
 loc: 620

host_vars/las118.las.kit.edu

-ansible_user: gethmann
+ansible_user: root
 user_account: richter
 ip_suffix: 118
 loc: 620

host_vars/las120.las.kit.edu

-ansible_user: gethmann
+ansible_user: root
 user_account: tong
 ip_suffix: 120
 loc: 621

host_vars/las122.las.kit.edu

 # ansible_connection: local
-ansible_user: gethmann
+ansible_user: root
 user_account: petri
 ip_suffix: 122
 loc: 621

host_vars/las126.las.kit.edu

-ansible_user: gethmann
+ansible_user: root
 user_account: gethmann
 ip_suffix: 126
 loc: 618