HttpBinaryCacheStore::getFile(): Fix uncaught exception

This method is marked as `noexcept`, but `enqueueFileTransfer()` can
throw `Interrupted` if the user has hit Ctrl-C or if the `ThreadPool`
that the thread is a part of is shutting down.

src/libstore/http-binary-cache-store.cc

@@ -169,28 +169,29 @@ class HttpBinaryCacheStore : public virtual HttpBinaryCacheStoreConfig, public v
  {
  try {
  checkEnabled();
+
+ auto request(makeRequest(path));
+
+ auto callbackPtr = std::make_shared<decltype(callback)>(std::move(callback));
+
+ getFileTransfer()->enqueueFileTransfer(request,
+ {[callbackPtr, this](std::future<FileTransferResult> result) {
+ try {
+ (*callbackPtr)(std::move(result.get().data));
+ } catch (FileTransferError & e) {
+ if (e.error == FileTransfer::NotFound || e.error == FileTransfer::Forbidden)
+ return (*callbackPtr)({});
+ maybeDisable();
+ callbackPtr->rethrow();
+ } catch (...) {
+ callbackPtr->rethrow();
+ }
+ }});
+
  } catch (...) {
  callback.rethrow();
  return;
  }
-
- auto request(makeRequest(path));
-
- auto callbackPtr = std::make_shared<decltype(callback)>(std::move(callback));
-
- getFileTransfer()->enqueueFileTransfer(request,
- {[callbackPtr, this](std::future<FileTransferResult> result) {
- try {
- (*callbackPtr)(std::move(result.get().data));
- } catch (FileTransferError & e) {
- if (e.error == FileTransfer::NotFound || e.error == FileTransfer::Forbidden)
- return (*callbackPtr)({});
- maybeDisable();
- callbackPtr->rethrow();
- } catch (...) {
- callbackPtr->rethrow();
- }
- }});
  }
 
  /**