Update freeradius-client.h

Fix the following error when compiling freeradius mod_radius_cdr:
 error: ISO C does not permit named variadic macros [-Werror=variadic-macros]
Merge pull request #11 from neuhaus/patch-1

Update freeradius-client.h
Fix handling of PW_TYPE_DATE avp.
Value of type PW_TYPE_DATE produces just 1 byte output, length and data are missing, subsequent avp are misaligned.
Merge pull request #12 from schochchr/master

Fix handling of PW_TYPE_DATE