Revert "Increase permissions on setCommon"

This reverts commit bb840fc.

Author: cujomalainey

src/RX/ANT_AntResponse.h

@@ -136,8 +136,8 @@ class AntResponse {
 protected:
     // pointer to frameData
     uint8_t* _frameDataPtr;
-    void setCommon(AntResponse &target);
 private:
+    void setCommon(AntResponse &target);
     uint8_t _msgId;
     uint8_t _length;
     uint8_t _checksum;