Make sure Exceptions do not use unsafe format strings
diff --git a/common/rfb/JpegCompressor.cxx b/common/rfb/JpegCompressor.cxx
index c19af34..5df0039 100644
--- a/common/rfb/JpegCompressor.cxx
+++ b/common/rfb/JpegCompressor.cxx
@@ -123,7 +123,7 @@
 
   if(setjmp(err->jmpBuffer)) {
     // this will execute if libjpeg has an error
-    throw rdr::Exception(err->lastError);
+    throw rdr::Exception("%s", err->lastError);
   }
 
   jpeg_create_compress(cinfo);
@@ -166,7 +166,7 @@
     jpeg_abort_compress(cinfo);
     if (srcBufIsTemp && srcBuf) delete[] srcBuf;
     if (rowPointer) delete[] rowPointer;
-    throw rdr::Exception(err->lastError);
+    throw rdr::Exception("%s", err->lastError);
   }
 
   cinfo->image_width = w;