Improve crash handling and logging

Monal/Classes/HelperTools.m

@@ -174,6 +174,7 @@ static void crash_callback(const KSCrashReportWriter* writer)
     int copyRetval = asyncSafeCopyFile(_origLogfilePath, _logfilePath);
     writer->addStringElement(writer, "logfileCopied", "YES");
     writer->addIntegerElement(writer, "logfileCopyResult", copyRetval);
+    writer->addIntegerElement(writer, "logfileCopyErrno", errno);
     addFilePathWithSize(writer, "logfileCopy", _logfilePath);
     //this comes last to make sure we see size differences if the logfile got written during crash data collection (could be other processes)
     addFilePathWithSize(writer, "currentLogfile", _origLogfilePath);
@@ -280,7 +281,6 @@ +(void) __attribute__((noreturn)) handleRustPanicWithText:(NSString*) text andBa
     _crash_info.message = abort_msg.UTF8String;
     _crash_info.signature = abort_msg.UTF8String;       //use signature for apple crash reporter which does not handle message field
     _crash_info.backtrace = backtrace.UTF8String;
-    _crash_info.message2 = backtrace.UTF8String;        //use message2 for kscrash which does not handle backtrace field
 
     //log error and flush all logs
     [DDLog flushLog];