Fix a bug in the config check logic

Summary: Since `cfg_get_bool` will return the default value when there is no key found for the config "disable_hg_autopullcommits" and we want to keep the original behavior for this case, we should revert the default boolean value (`False`) to `True`.

Reviewed By: genevievehelsel

Differential Revision: D72365523

fbshipit-source-id: 73f9c8ce211dfb0fa7e2ef27f2287be50f159cb6

Author: lXXXw

third-party/watchman/src/watchman/scm/Mercurial.cpp

@@ -165,7 +165,7 @@ w_string Mercurial::mergeBaseWith(
           [this, commit, requestId](const std::string&) {
             auto revset = fmt::format("ancestor(.,{})", commit);
             MercurialResult result;
-            if (cfg_get_bool("disable_hg_autopullcommits", false)) {
+            if (!cfg_get_bool("disable_hg_autopullcommits", false)) {
               result = runMercurial(
                   {hgExecutablePath(), "log", "-T", "{node}", "-r", revset},
                   makeHgOptions(requestId),