Always set FTZ instead of gating it behind a flag

After a quick round of testing it seems like REAPER doesn't always
enable this on the audio thread, but Bitwig, Ardour, Carla and Renoise
do. So it should be safe to just get rid of the option and to leave this
enabled all the time.

src/common/configuration.cpp

@@ -108,12 +108,6 @@ Configuration::Configuration(const fs::path& config_path,
                 } else {
                     invalid_options.push_back(key);
                 }
-            } else if (key == "force_ftz") {
-                if (const auto parsed_value = value.as_boolean()) {
-                    force_ftz = parsed_value->get();
-                } else {
-                    invalid_options.push_back(key);
-                }
             } else if (key == "frame_rate") {
                 if (const auto parsed_value = value.as_floating_point()) {
                     frame_rate = parsed_value->get();

src/common/configuration.h

@@ -126,15 +126,6 @@ class Configuration {
      */
     bool editor_xembed = false;
 
-    /**
-     * When using this option, we'll enable the flush-to-zero flag during audio
-     * processing. This can be useful when the host passes denormals to a plugin
-     * that doesn't handle those well. An example of such a plugin is REDDI by
-     * Kush Audio. Some hosts, like Bitwig, will already snap denormals to zero
-     * for us so this may not be necessary with every host.
-     */
-    bool force_ftz = false;
-
     /**
      * The number of times per second we'll handle the event loop. In most
      * plugins this also controls the plugin editor GUI's refresh rate.
@@ -214,7 +205,6 @@ class Configuration {
         s.value1b(editor_double_embed);
         s.value1b(editor_force_dnd);
         s.value1b(editor_xembed);
-        s.value1b(force_ftz);
         s.ext(frame_rate, bitsery::ext::StdOptional(),
               [](S& s, auto& v) { s.value4b(v); });
         s.value1b(hide_daw);