Update messages/webapp.dev.md

Co-authored-by: Juliet Shackell <63259011+jshackell-sfdc@users.noreply.github.com>

Author: deepu-mungamuri94

messages/webapp.dev.md

@@ -96,7 +96,7 @@ Proxy URL: %s (open this URL in your browser)
 
 # info.press-ctrl-c
 
-Press Ctrl+C to stop
+Press Ctrl+C to stop.
 
 # info.press-ctrl-c-target