osmo-trx-ms: bump osmocom-bb submodule commit

The new revision contains an important fix [1] for GPRS scheduling.

Change-Id: Ibb57b29bb0424a40836819c15d25d1133f554d32
Related: [1] osmocom-bb.git I439615639b8e840b9fd4f3af6934d9f298f32216
Related: OS#5500
diff --git a/osmocom-bb b/osmocom-bb
index 05ddc05..a41ca4b 160000
--- a/osmocom-bb
+++ b/osmocom-bb
@@ -1 +1 @@
-Subproject commit 05ddc05233100236d93c1268a1d851b14efc6fca
+Subproject commit a41ca4bbc42bc66557cdc7c646c539d1a4c1e30f