remove lmdbbackend symlink from regressio-tests modules dir

diff --git a/regression-tests/modules/liblmdbbackend.so b/regression-tests/modules/liblmdbbackend.so
deleted file mode 120000 (symlink)
index 52c0801..0000000
--- a/regression-tests/modules/liblmdbbackend.so
+++ /dev/null
@@ -1 +0,0 @@
-../../modules/lmdbbackend/.libs/liblmdbbackend.so
\ No newline at end of file