Transceiver: Initialize mExtRACH in constructor

Doing so should make Coverity happy:
>>>     CID 200212:  Uninitialized members  (UNINIT_CTOR)
>>>     Non-static class member "mExtRACH" is not initialized in this constructor nor in any functions that it calls.

The current status is actually harmless since the field will be set
during init() time, and the variable is never used before init() is
called.

Fixes: Coverity CID#200212
Change-Id: I17286570a9a6db695a75147e5cbb18c9da7d0fe6
diff --git a/Transceiver52M/Transceiver.cpp b/Transceiver52M/Transceiver.cpp
index 0a832f0..17e0476 100644
--- a/Transceiver52M/Transceiver.cpp
+++ b/Transceiver52M/Transceiver.cpp
@@ -124,7 +124,8 @@
   : mBasePort(wBasePort), mLocalAddr(TRXAddress), mRemoteAddr(GSMcoreAddress),
     mClockSocket(-1), mTransmitLatency(wTransmitLatency), mRadioInterface(wRadioInterface),
     rssiOffset(wRssiOffset), stackSize(wStackSize),
-    mSPSTx(tx_sps), mSPSRx(rx_sps), mChans(chans), mEdge(false), mOn(false), mForceClockInterface(false),
+    mSPSTx(tx_sps), mSPSRx(rx_sps), mChans(chans), mExtRACH(false), mEdge(false),
+    mOn(false), mForceClockInterface(false),
     mTxFreq(0.0), mRxFreq(0.0), mTSC(0), mMaxExpectedDelayAB(0), mMaxExpectedDelayNB(0),
     mWriteBurstToDiskMask(0), mVersionTRXD(0)
 {