http: leverage 'bindaddr' for TLS in http.conf

The internal HTTP/WebSocket server supports both TCP and TLS, which can be
activated separately via the file http.conf. The source code intends to re-use
the TCP parameter 'bindaddr' for TLS, even if 'tlsbindaddr' is not specified
explicitly. This did not work because of a typo. This change resolves this typo.

ASTERISK-26126 #close

Change-Id: I5efb0409ae12044dfb3495b6b97b6d40a8c9c51f