Require KeyboardInterrupt to stop discovery

Otherwise discovery would stop after entering key passphrase

README.md

@@ -58,7 +58,7 @@ Sending a file is typically a two-step procedure. You first discover devices in
 Stop the process once you have found the receiver.
 ```
 $ opendrop find
-Looking for receivers. Press enter to stop ...
+Looking for receivers. Press Ctrl+C to stop ...
 Found  index 0  ID eccb2f2dcfe7  name John’s iPhone
 Found  index 1  ID e63138ac6ba8  name Jane’s MacBook Pro
 ```

opendrop/cli.py

@@ -113,11 +113,12 @@ class AirDropCli:
                 self.server.stop()
 
     def find(self):
-        logger.info("Looking for receivers. Press enter to stop ...")
+        logger.info("Looking for receivers. Press Ctrl+C to stop ...")
         self.browser = AirDropBrowser(self.config)
         self.browser.start(callback_add=self._found_receiver)
         try:
-            input()
+            while True:
+                pass
         except KeyboardInterrupt:
             pass
         finally: