Remove magic JPEG variables from ConnParams

Custom compression level and JPEG on/off are not inherent parts of
the protocol negotiation so they do not belong in ConnParams. Let the
UI frontend handle such things instead.
diff --git a/common/rfb/CMsgWriter.cxx b/common/rfb/CMsgWriter.cxx
index 0ebd33e..9ee7a02 100644
--- a/common/rfb/CMsgWriter.cxx
+++ b/common/rfb/CMsgWriter.cxx
@@ -114,9 +114,9 @@
     }
   }
 
-  if (cp->customCompressLevel && cp->compressLevel >= 0 && cp->compressLevel <= 9)
+  if (cp->compressLevel >= 0 && cp->compressLevel <= 9)
       encodings[nEncodings++] = pseudoEncodingCompressLevel0 + cp->compressLevel;
-  if (!cp->noJpeg && cp->qualityLevel >= 0 && cp->qualityLevel <= 9)
+  if (cp->qualityLevel >= 0 && cp->qualityLevel <= 9)
       encodings[nEncodings++] = pseudoEncodingQualityLevel0 + cp->qualityLevel;
 
   writeSetEncodings(nEncodings, encodings);