Merge fort-nix/nix-bitcoin#829: run-vm.sh: fix SSH auth error due to agent keys

f5b2e5eb9f run-vm.sh: fix SSH auth error due to agent keys (Erik Arvstedt)

Pull request description:

ACKs for top commit:
  jonasnick:
    ACK f5b2e5eb9f

Tree-SHA512: 467cc0e574a2be14f0d27cbd75d55a4ab0994b7fc00f6cccf112bf073aa20d7963f829d29b9b14af3d13130a8c5986d54ec6974f73ad75589ec6c7605b32d721

examples/qemu-vm/run-vm.sh

@@ -41,7 +41,7 @@ vmWaitForSSH() {
 
 # Run command in VM
 c() {
-    ssh -p "$sshPort" -i "$identityFile" -o ConnectTimeout=1 \
+    ssh -p "$sshPort" -i "$identityFile" -o IdentitiesOnly=yes -o ConnectTimeout=1 \
         -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -o LogLevel=ERROR \
         -o ControlMaster=auto -o ControlPath=$tmpDir/ssh-connection -o ControlPersist=60 \
         root@127.0.0.1 "$@"