qt: Fix QFileDialog for static builds

This change partially reverts 248e22b.

Author: hebasto

depends/packages/qt.mk

@@ -80,7 +80,6 @@ $(package)_config_opts += -no-feature-colordialog
 $(package)_config_opts += -no-feature-commandlineparser
 $(package)_config_opts += -no-feature-concurrent
 $(package)_config_opts += -no-feature-dial
-$(package)_config_opts += -no-feature-filesystemwatcher
 $(package)_config_opts += -no-feature-fontcombobox
 $(package)_config_opts += -no-feature-ftp
 $(package)_config_opts += -no-feature-http