Revert "Merge pull request #5742 from nextcloud/backport/5707/stable-3.9"

This reverts commit 5118bcfaba1595e52a1eabd30b4012b875bc1fde, reversing
changes made to d9603fc84cd81b44da085bd824321167c935125b.

Signed-off-by: Claudio Cambra <claudio.cambra@nextcloud.com>

config.h.in

@@ -4,7 +4,6 @@
 #cmakedefine USE_INOTIFY 1
 #cmakedefine WITH_QTKEYCHAIN 1
 #cmakedefine WITH_CRASHREPORTER
-#cmakedefine BUILD_FILE_PROVIDER_MODULE 1
 #cmakedefine WITH_PROVIDERS "@WITH_PROVIDERS@"
 #cmakedefine CRASHREPORTER_EXECUTABLE "@CRASHREPORTER_EXECUTABLE@"
 #define SOCKETAPI_TEAM_IDENTIFIER_PREFIX "@SOCKETAPI_TEAM_IDENTIFIER_PREFIX@"

src/gui/application.cpp

@@ -403,7 +403,7 @@ Application::Application(int &argc, char **argv)
         }
     }
 
-#if defined(BUILD_FILE_PROVIDER_MODULE)
+#if defined(Q_OS_MACOS)
     _fileProvider.reset(new Mac::FileProvider);
 #endif