qa: Fix lcov for out-of-tree builds

configure.ac

@@ -1231,6 +1231,7 @@ AC_SUBST(QR_LIBS)
 AC_CONFIG_FILES([Makefile src/Makefile doc/man/Makefile share/setup.nsi share/qt/Info.plist test/config.ini])
 AC_CONFIG_FILES([contrib/devtools/split-debug.sh],[chmod +x contrib/devtools/split-debug.sh])
 AC_CONFIG_FILES([doc/Doxyfile])
+AC_CONFIG_LINKS([contrib/filter-lcov.py:contrib/filter-lcov.py])
 AC_CONFIG_LINKS([test/functional/test_runner.py:test/functional/test_runner.py])
 AC_CONFIG_LINKS([test/util/bitcoin-util-test.py:test/util/bitcoin-util-test.py])