units: disallow manual starting of passive units

As passive units only are useful for ordering things within the initial
transaction there is no point in ever activating them manually, hence
refuse it.

units/local-fs-pre.target

@@ -8,3 +8,4 @@
 [Unit]
 Description=Local File Systems (Pre)
 Documentation=man:systemd.special(7)
+RefuseManualStart=yes

units/nss-lookup.target

@@ -11,3 +11,4 @@
 [Unit]
 Description=Host and Network Name Lookups
 Documentation=man:systemd.special(7)
+RefuseManualStart=yes

units/nss-user-lookup.target

@@ -11,3 +11,4 @@
 [Unit]
 Description=User and Group Name Lookups
 Documentation=man:systemd.special(7)
+RefuseManualStart=yes

units/remote-fs-pre.target

@@ -8,3 +8,4 @@
 [Unit]
 Description=Remote File Systems (Pre)
 Documentation=man:systemd.special(7)
+RefuseManualStart=yes

units/rpcbind.target

@@ -11,3 +11,4 @@
 [Unit]
 Description=RPC Port Mapper
 Documentation=man:systemd.special(7)
+RefuseManualStart=yes

units/time-sync.target

@@ -11,3 +11,4 @@
 [Unit]
 Description=System Time Synchronized
 Documentation=man:systemd.special(7)
+RefuseManualStart=yes