Implement the HSL SR1.0.1 protocol

It seems HSL has fixed most of their obvious issues in the SR1.0.1
release.  However, this creates quite an incompatibility of the
protocol, and we have to adapt accordingly
diff --git a/openbsc/src/libbsc/bsc_init.c b/openbsc/src/libbsc/bsc_init.c
index 0072bb6..37386d7 100644
--- a/openbsc/src/libbsc/bsc_init.c
+++ b/openbsc/src/libbsc/bsc_init.c
@@ -397,7 +397,7 @@
 	if (bts->network->dtx_enabled)
 		bts->si_common.cell_options.dtx = 0;
 	else
-		bts->si_common.cell_options.dtx = 2;
+		bts->si_common.cell_options.dtx = 3;
 
 	bts->si_common.cell_options.pwrc = 0; /* PWRC not set */