testing: Globally define logging via syslog for charon-systemd

We could make the same change for charon (actually setting it for charon
in strongswan.conf.testing would work for charon-systemd too), however,
there are dozens of test cases that currently set charondebug in
ipsec.conf.

testing/tests/swanctl/protoport-range/hosts/carol/etc/strongswan.conf

@@ -2,13 +2,4 @@
 
 charon-systemd {
   load = random nonce aes sha1 sha2 pem pkcs1 curve25519 gmp x509 curl revocation hmac vici kernel-netlink socket-default updown
-
-  syslog {
-    daemon {
-      default = 1
-    }
-    auth {
-      default = 0
-    }
-  }
 }

testing/tests/swanctl/protoport-range/hosts/moon/etc/strongswan.conf

@@ -2,13 +2,4 @@
 
 charon-systemd {
   load = random nonce aes sha1 sha2 pem pkcs1 curve25519 gmp x509 curl revocation hmac vici kernel-netlink socket-default updown
-
-  syslog {
-    daemon {
-      default = 1
-    }
-    auth {
-      default = 0
-    }
-  }
 }