bts: TC_pcu_{time,rts}_ind: Higher tolerances

When executing the test on our build slaves, we ran into the following:

> Number of TDMA Frames (1100) not matching (1073 .. 1093)
> Number of TDMA Frames (1096) not matching (1073 .. 1093)

So it seems the tolerance was a bit too tight.  If the timer runs
for a bit more than the requested amount of seconds (e.g. due to
high system load), the number of TDMA frames is likely a bit higher
and hence we need to permit a larger tolerance.

Change-Id: Ib00bb7e7f223fb0329d00e3835127b8c31299e27
diff --git a/bts/BTS_Tests.ttcn b/bts/BTS_Tests.ttcn
index 6786d68..968ed6c 100644
--- a/bts/BTS_Tests.ttcn
+++ b/bts/BTS_Tests.ttcn
@@ -3713,7 +3713,7 @@
 	/* verify the number of frames expired matches our expectation */
 	const float c_GSM_FN_DURATION_MS := 4.61538;
 	var float fn_expected := test_duration * 1000.0 / c_GSM_FN_DURATION_MS;
-	var template integer t_fn_expected := f_tolerance(float2int(fn_expected), 1, 100000, 10);
+	var template integer t_fn_expected := f_tolerance(float2int(fn_expected), 1, 100000, 20);
 	if (not match(fn_expired, t_fn_expected)) {
 		setverdict(fail, "Number of TDMA Frames (", fn_expired, ") not matching ", t_fn_expected);
 	}
@@ -3778,7 +3778,7 @@
 	/* verify the number of frames expired matches our expectation */
 	const float c_GSM_FN_DURATION_MS := 4.61538;
 	var float fn_expected := test_duration * 1000.0 / c_GSM_FN_DURATION_MS;
-	var template integer t_fn_expected := f_tolerance(float2int(fn_expected), 1, 100000, 10);
+	var template integer t_fn_expected := f_tolerance(float2int(fn_expected), 1, 100000, 20);
 	if (not match(fn_expired, t_fn_expected)) {
 		setverdict(fail, "Number of TDMA Frames (", fn_expired, ") not matching ", t_fn_expected);
 	}