message: build: only pass -optimized-tools to qt in debug mode
  Qt's configure tells us that "-optimized-tools is not useful in -release
  mode.", so don't use it there.
diff: @@ -26,6 +26,7 @@ define $(package)_set_vars
  $(package)_config_opts_release = -release
  $(package)_config_opts_release += -silent
  $(package)_config_opts_debug = -debug
  +$(package)_config_opts_debug += -optimized-tools
  $(package)_config_opts += -bindir $(build_prefix)/bin
  $(package)_config_opts += -c++std c++1z
  $(package)_config_opts += -confirm-license
  @@ -67,7 +68,6 @@ $(package)_config_opts += -no-xinput2
  $(package)_config_opts += -nomake examples
  $(package)_config_opts += -nomake tests
  $(package)_config_opts += -opensource
  -$(package)_config_opts += -optimized-tools
  $(package)_config_opts += -pkg-config
  $(package)_config_opts += -prefix $(host_prefix)
  $(package)_config_opts += -qt-libpng
  