dist: add symbol-scan.pl to the tarball

... in order to make test1135 succeed

Author: kdudka

tests/Makefile.am

@@ -27,7 +27,7 @@ EXTRA_DIST = ftpserver.pl httpserver.pl secureserver.pl runtests.pl getpart.pm \
  FILEFORMAT README stunnel.pem memanalyze.pl testcurl.pl valgrind.pm ftp.pm   \
  sshserver.pl sshhelp.pm testcurl.1 runtests.1 $(HTMLPAGES) $(PDFPAGES) \
  serverhelp.pm tftpserver.pl rtspserver.pl directories.pm symbol-scan.pl \
- CMakeLists.txt mem-include-scan.pl valgrind.supp http_pipe.py
+ CMakeLists.txt mem-include-scan.pl valgrind.supp http_pipe.py extern-scan.pl
 
 DISTCLEANFILES = configurehelp.pm