Bug#747540: soundscaperenderer: FTBFS on non-amd64: looks for Boost in the wrong place

[Aaron M. Ucko]

Source: soundscaperenderer
Version: 0.4.1~dfsg-1
Severity: important
Justification: fails to build from source

Builds of soundscaperenderer for architectures other than amd64 have
been failing with the errors

  checking for boost_system library... not found! (Use BOOST_LIB_DIR to specify a directory.)
  checking for boost_thread library... not found! (Use BOOST_LIB_DIR to specify a directory.)
  configure: error: ip-interface (network (TCP/IP) interface) not available! Use --disable-ip-interface to deactivate.

even though soundscaperenderer properly lists libboost-system-dev and
libboost-thread-dev in Build-Depends.  The problem appears to stem
from looking only in a specific set of locations, presumably to account
for possible library-name tags:

  for dir in $BOOST_LIB_DIR /{usr,opt}/{local/,}lib{,64}{,/x86_64-linux-gnu}; do

I believe setting BOOST_LIB_DIR to /usr/lib/$(DEB_HOST_MULTIARCH)
should remedy that; could you please give it a try?

Thanks!