[#3052] Required version for Celt updated to 0.7.1 configure.ac

sflphone-common/configure.ac

@@ -357,7 +357,7 @@ AC_DEFINE([HAVE_SPEEX], test "x$with_speex" = "xyes", [Define if you have libspe
 AM_CONDITIONAL(ENABLE_SPEEXDSP, test  $HAVE_SPEEXDSP = yes)
 
 	dnl Check for celt. Compile it only if a recent enough version is found
-	LIBCELT_MIN_VERSION=0.5.1
+	LIBCELT_MIN_VERSION=0.7.1
 PKG_CHECK_MODULES(CELT, celt >= ${LIBCELT_MIN_VERSION}, AM_CONDITIONAL(BUILD_CELT, test 1 = 1 ), AM_CONDITIONAL(BUILD_CELT, test 0 = 1 ))
 
 	dnl Check for IAX