Move vasprintf/drand48 check after we set all cflags.
Move vasprintf/drand48 check after we set all cflags.

sippy/rtpproxy,Vocalocity/rtpproxy-pre,hongbinz/rtpproxy,hongbinz/rtpproxy,jevonearth/rtpproxy,sippy/rtpproxy,synety-jdebp/rtpproxy,dsanders11/rtpproxy,synety-jdebp/rtpproxy,jevonearth/rtpproxy,synety-jdebp/rtpproxy,jevonearth/rtpproxy,Vocalocity/rtpproxy-pre,hongbinz/rtpproxy,hongbinz/rtpproxy,jevonearth/rtpproxy,Vocalocity/rtpproxy-pre,synety-jdebp/rtpproxy,Vocalocity/rtpproxy-pre,sippy/rtpproxy,dsanders11/rtpproxy,dsanders11/rtpproxy