fix various warnings

Change-Id: I2794c1d374654870985a655a42ac647ff66c97a1
Reviewed-by: Philippe Gorley <philippe.gorley@savoirfairelinux.com>

src/account.h

@@ -61,7 +61,7 @@ namespace ring {
 
 class Call;
 class SystemCodecContainer;
-class IceTransportOptions;
+struct IceTransportOptions;
 
 class VoipLinkException : public std::runtime_error
 {

src/im/message_engine.cpp

@@ -53,7 +53,7 @@ MessageEngine::sendMessage(const std::string& to, const std::map<std::string, st
         m.first->second.payloads = payloads;
     }
     save();
-    runOnMainThread([this,token]() {
+    runOnMainThread([this]() {
         retrySend();
     });
     return token;

src/media/media_encoder.h

@@ -37,11 +37,11 @@
 #include <string>
 #include <vector>
 
-class AVCodecContext;
-class AVStream;
-class AVFormatContext;
-class AVDictionary;
-class AVCodec;
+struct AVCodecContext;
+struct AVStream;
+struct AVFormatContext;
+struct AVDictionary;
+struct AVCodec;
 
 namespace ring {
 

src/media/video/video_base.h

@@ -36,11 +36,11 @@
 #include <mutex>
 #include <ciso646> // fix windows compiler bug
 
-class AVPacket;
-class AVDictionary;
+struct AVPacket;
+struct AVDictionary;
 
 #ifndef AVFORMAT_AVIO_H
-class AVIOContext;
+struct AVIOContext;
 #endif
 
 namespace ring {