minor improvements to scripts

scripts/block_headers

@@ -16,5 +16,5 @@ callback = lambda _,result: electrum.print_json(result.get('result'))
 interface.send([('blockchain.headers.subscribe',[])], callback)
 
 # 3. wait for results
-while True:
+while interface.is_connected:
     time.sleep(1)

scripts/peers

@@ -72,7 +72,7 @@ while reached_servers:
 errors = analyze(results).keys()
 
 for n,v in results.items():
-    print "%30s"%n, v['block_height'], v['utxo_root'], "error" if n in errors else "ok"
+    print "%40s"%n, v['block_height'], v['utxo_root'], "error" if n in errors else "ok"