add LogNamespace to systemd units (#16454)

system/systemd/netdata.service.in

@@ -6,6 +6,7 @@ Description=Real time performance monitoring
 After=network.target
 
 [Service]
+LogNamespace=netdata
 Type=simple
 User=root
 RuntimeDirectory=netdata

system/systemd/netdata.service.v235.in

@@ -6,6 +6,7 @@ Description=Real time performance monitoring
 After=network.target
 
 [Service]
+LogNamespace=netdata
 Type=simple
 User=root
 EnvironmentFile=-/etc/default/netdata