Remove qDebug statement from registerCompressionLibraries()

This commit remove the debug statement originally introduced in 5f1616f.

Before this commit the text:

   Register compression libraries

was displayed each time the application instantiating the DICOM
database was started.

Libs/DICOM/Core/ctkDICOMDatabase.cpp

@@ -182,7 +182,6 @@ void ctkDICOMDatabasePrivate::init(QString databaseFilename)
 
 //------------------------------------------------------------------------------
 void ctkDICOMDatabasePrivate::registerCompressionLibraries(){
-  logger.debug("Register compression libraries");
   // Register the JPEG libraries in case we need them
   //   (registration only happens once, so it's okay to call repeatedly)
   // register global JPEG decompression codecs
@@ -1212,14 +1211,14 @@ void ctkDICOMDatabasePrivate::insert( const ctkDICOMItem& ctkDataset, const QStr
 
   // this is the method that all other insert signatures end up calling
   // after they have pre-parsed their arguments
- 
+
   // Check to see if the file has already been loaded
   // TODO:
   // It could make sense to actually remove the dataset and re-add it. This needs the remove
   // method we still have to write.
   //
   //
-  
+
   QString sopInstanceUID ( ctkDataset.GetElementAsString(DCM_SOPInstanceUID) );
 
   QSqlQuery fileExistsQuery ( Database );