Change reference initializations errors in GCC 4.8

Resolves issue #12.

firmware/baseband/dsp_decimate.hpp

@@ -60,7 +60,7 @@ public:
 
 	FIR64AndDecimateBy2Real(
 		const std::array<int16_t, taps_count>& taps
-	) : taps { taps }
+	) : taps(taps)
 	{
 	}
 

firmware/baseband/main.cpp

@@ -582,7 +582,7 @@ class FSKProcessor : public BasebandProcessor {
 public:
 	FSKProcessor(
 		MessageHandlerMap& message_handlers
-	) : message_handlers { message_handlers }
+	) : message_handlers(message_handlers)
 	{
 		message_handlers[Message::ID::FSKConfiguration] = [this](const Message* const p) {
 			auto m = reinterpret_cast<const FSKConfigurationMessage*>(p);