test: use random port/rpcport for bitcoind.

This means we don't get confused if a testnet bitcoind already running.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

daemon/test/scripts/vars.sh

@@ -11,4 +11,10 @@ else
 	SEQ_ENFORCEMENT=false
 fi
 
+findport()
+{
+    PORT=$1
+    while netstat -ntl | grep -q ":$PORT "; do PORT=$(($PORT + 1)); done
+    echo $PORT
+}
 #PREFIX="valgrind --vgdb-error=1"