testing: Rename public keys in DNSSEC scenarios

We will generate PEM-encoded public keys with the script.

testing/tests/swanctl/rw-dnssec/hosts/carol/etc/swanctl/swanctl.conf

@@ -2,13 +2,13 @@ connections {
 
    home {
       local_addrs  = 192.168.0.100
-      remote_addrs = 192.168.0.1 
+      remote_addrs = 192.168.0.1
       vips = 0.0.0.0
 
       local {
          auth = pubkey
          id = carol.strongswan.org
-         pubkeys = carolPub.der
+         pubkeys = carolPub.pem
       }
       remote {
          auth = pubkey
@@ -16,7 +16,7 @@ connections {
       }
       children {
          home {
-            remote_ts = 10.1.0.0/16 
+            remote_ts = 10.1.0.0/16
 
             updown = /usr/local/libexec/ipsec/_updown iptables
             esp_proposals = aes128gcm128-x25519

testing/tests/swanctl/rw-dnssec/hosts/dave/etc/swanctl/swanctl.conf

@@ -2,13 +2,13 @@ connections {
 
    home {
       local_addrs  = 192.168.0.200
-      remote_addrs = 192.168.0.1 
+      remote_addrs = 192.168.0.1
       vips = 0.0.0.0
 
       local {
          auth = pubkey
          id = dave.strongswan.org
-         pubkeys = davePub.der
+         pubkeys = davePub.pem
       }
       remote {
          auth = pubkey
@@ -16,7 +16,7 @@ connections {
       }
       children {
          home {
-            remote_ts = 10.1.0.0/16 
+            remote_ts = 10.1.0.0/16
 
             updown = /usr/local/libexec/ipsec/_updown iptables
             esp_proposals = aes128gcm128-x25519

testing/tests/swanctl/rw-dnssec/hosts/moon/etc/swanctl/swanctl.conf

@@ -7,14 +7,14 @@ connections {
       local {
          auth = pubkey
          id = moon.strongswan.org
-         pubkeys = moonPub.der
+         pubkeys = moonPub.pem
       }
       remote {
          auth = pubkey
       }
       children {
          net {
-            local_ts  = 10.1.0.0/16 
+            local_ts  = 10.1.0.0/16
 
             updown = /usr/local/libexec/ipsec/_updown iptables
             esp_proposals = aes128gcm128-x25519