IceTransport: make isTCPEnabled const

Change-Id: I869fcb8903654558c39afa4f9d4aaefecd7cb40a

include/ice_transport.h

@@ -184,7 +184,7 @@ public:
     bool setSlaveSession();
     bool setInitiatorSession();
 
-    bool isTCPEnabled();
+    bool isTCPEnabled() const;
 
     ICESDP parseIceCandidates(std::string_view sdp_msg);
 

src/ice_transport.cpp

@@ -1742,7 +1742,7 @@ IceTransport::waitForData(unsigned compId, std::chrono::milliseconds timeout, st
 }
 
 bool
-IceTransport::isTCPEnabled()
+IceTransport::isTCPEnabled() const
 {
     return pimpl_->isTcpEnabled();
 }