Add missing build requirement in Debian package.

debian/control

@@ -4,7 +4,8 @@ Maintainer: Thomas Moulard <thomas.moulard@gmail.com>
 Build-Depends: debhelper (>= 7.0.50~), cmake (>= 2.6),
 	       doxygen (>= 1.6.3),
 	       pkg-config (>= 0.22),
-	       libboost-dev (>= 1.33.1)
+	       libboost-dev (>= 1.33.1),
+	       libboost-thread-dev (>= 1.33.1)
 Standards-Version: 3.8.4
 #Vcs-Git:
 #Vcs-browser: