[Unit-tests] Add --enable-fake-dlclose configure flag so modules are not unloaded and ASAN could give more info and not just <unknown module>.

src/switch_dso.c

@@ -91,7 +91,9 @@ SWITCH_DECLARE(void *) switch_dso_data_sym(switch_dso_lib_t lib, const char *sym
 void switch_dso_destroy(switch_dso_lib_t *lib)
 {
 	if (lib && *lib) {
+#ifndef HAVE_FAKE_DLCLOSE
 		dlclose(*lib);
+#endif
 		*lib = NULL;
 	}
 }