Plugin: remove unused base64.h header

plugins/bit_invader/bit_invader.cpp

@@ -26,6 +26,7 @@
 #include <QtXml/QDomElement>
 
 #include "bit_invader.h"
+#include "base64.h"
 #include "engine.h"
 #include "graph.h"
 #include "InstrumentTrack.h"

plugins/dynamics_processor/dynamics_processor_controls.cpp

@@ -28,6 +28,7 @@
 
 #include "dynamics_processor_controls.h"
 #include "dynamics_processor.h"
+#include "base64.h"
 #include "graph.h"
 #include "engine.h"
 #include "song.h"

plugins/papu/papu_instrument.cpp

@@ -29,6 +29,7 @@
 #include "Basic_Gb_Apu.h"
 
 #include "papu_instrument.h"
+#include "base64.h"
 #include "InstrumentTrack.h"
 #include "knob.h"
 #include "NotePlayHandle.h"

plugins/watsyn/Watsyn.cpp

@@ -25,6 +25,7 @@
 #include <QtXml/QDomElement>
 
 #include "Watsyn.h"
+#include "base64.h"
 #include "engine.h"
 #include "InstrumentTrack.h"
 #include "templates.h"

plugins/waveshaper/waveshaper_controls.cpp

@@ -28,6 +28,7 @@
 
 #include "waveshaper_controls.h"
 #include "waveshaper.h"
+#include "base64.h"
 #include "graph.h"
 #include "engine.h"
 #include "song.h"