ifconfig(8): Change constructor priorities from 100 to 101.

ifconfig(8): Change constructor priorities from 100 to 101.

This silences some gcc44 warnings.

Constructor priorities are bounded between 101 and 65535 inclusive.
0 to 100 are reserved for the implementation.

See also:

http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html
http://gcc.gnu.org/onlinedocs/gcc/C_002b_002b-Attributes.html