Tiny Handbook Fix

[Craig Reyenga]

I noticed a small error in the handbook:

19.2.7 Multicast Routing

FreeBSD supports both multicast applications and multicast routing natively.
Multicast applications do not require any special configuration of FreeBSD;
applications will generally run out of the box. Multicast routing requires
configuration requires that support be compiled into the kernel:


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Notice the "requires configuration requires" in the last sentence.

-Craig