Adjust default global effectable volume (#3272)

Originally introduced this in PR #1230

Bringing it back as we're always telling people to reduce their song volume to avoid clipping

But was reversed due to the change to the preset loading volume (that's not in this PR)

src/deluge/model/global_effectable/global_effectable.cpp

@@ -72,7 +72,7 @@ void GlobalEffectable::initParams(ParamManager* paramManager) {
 	unpatchedParams->params[params::UNPATCHED_DELAY_AMOUNT].setCurrentValueBasicForSetup(NEGATIVE_ONE_Q31);
 	unpatchedParams->params[params::UNPATCHED_REVERB_SEND_AMOUNT].setCurrentValueBasicForSetup(NEGATIVE_ONE_Q31);
 
-	unpatchedParams->params[params::UNPATCHED_VOLUME].setCurrentValueBasicForSetup(889516852); // 3/4 of the way up
+	unpatchedParams->params[params::UNPATCHED_VOLUME].setCurrentValueBasicForSetup(0); // half of the way up
 	unpatchedParams->params[params::UNPATCHED_SIDECHAIN_VOLUME].setCurrentValueBasicForSetup(NEGATIVE_ONE_Q31);
 	unpatchedParams->params[params::UNPATCHED_PITCH_ADJUST].setCurrentValueBasicForSetup(0);