debian: Add debDebFile::ExtractTarMember to the symbols file

debian/libapt-inst1.5.symbols

@@ -9,6 +9,7 @@ libapt-inst.so.1.5 libapt-inst1.5 #MINVER#
  (c++)"debDebFile::CheckMember(char const*)@Base" 0.8.0
  (c++)"debDebFile::ControlExtract::DoItem(pkgDirStream::Item&, int&)@Base" 0.8.0
  (c++)"debDebFile::ControlExtract::~ControlExtract()@Base" 0.8.0
+ (c++)"debDebFile::ExtractTarMember(pkgDirStream&, char const*)@Base" 0.9.15.4
  (c++)"debDebFile::ExtractArchive(pkgDirStream&)@Base" 0.8.0
  (c++)"debDebFile::MemControlExtract::TakeControl(void const*, unsigned long)@Base" 0.8.0
  (c++)"debDebFile::MemControlExtract::Read(debDebFile&)@Base" 0.8.0