kex.c: fix simple typo, niumber -> number (#545)
kex.c: fix simple typo, niumber -> number (#545)

File: kex.c

Notes:
There is a small typo in src/kex.c.

Should read `number` rather than `niumber`.

Credit:
Tim Gates
libssh2/libssh2,libssh2/libssh2,libssh2/libssh2,libssh2/libssh2