Fix config.port and config.bind

[DannyBen]

Fixes #145

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Since the command line refactoring in 1.0.0, both --port and --bind were defined like this:

madness/lib/madness/commands/server.rb

Line 11 in 65158e5

option '-p --port NUMBER', 'Set server port number [default: 3000]'

which meant that when we reached the config merge function here

madness/lib/madness/commands/server.rb

Lines 54 to 57 in 65158e5

	def override_config(args)
	config.path = args['PATH'] if args['PATH']
	config.port = args['--port'].to_i if args['--port']
	config.bind = args['--bind'] if args['--bind']

there was always a value in the command line arguments, which always shadows the config argument.

Replacing the square brackets with standard parentheses prevents this from happening.