Beta 4: Fixed crash in music player when updating player options: "this.model.audio_option[this.oldPlayer] is undefined"

ERROR TypeError: "this.model.audio_option[this.oldPlayer] is undefined"
onSubmithttp://lisa.springfield.home/0.b5b240a004abcd3eec15.chunk.js:1:573938alhttp://lisa.springfield.home/0.b5b240a004abcd3eec15.chunk.js:1:242416handleEventhttp://lisa.springfield.home/main.b9ed13a1b2f4fbe849db.bundle.js:1:218898handleEventhttp://lisa.springfield.home/main.b9ed13a1b2f4fbe849db.bundle.js:1:296289Ethttp://lisa.springfield.home/main.b9ed13a1b2f4fbe849db.bundle.js:1:198979shttp://lisa.springfield.home/main.b9ed13a1b2f4fbe849db.bundle.js:1:204510lhttp://lisa.springfield.home/main.b9ed13a1b2f4fbe849db.bundle.js:1:331542invokeTaskhttp://lisa.springfield.home/polyfills.b67d9fa4d5aa970cbe0f.bundle.js:1:128983onInvokeTaskhttp://lisa.springfield.home/main.b9ed13a1b2f4fbe849db.bundle.js:1:252347invokeTaskhttp://lisa.springfield.home/polyfills.b67d9fa4d5aa970cbe0f.bundle.js:1:128896runTaskhttp://lisa.springfield.home/polyfills.b67d9fa4d5aa970cbe0f.bundle.js:1:124153invokeTaskhttp://lisa.springfield.home/polyfills.b67d9fa4d5aa970cbe0f.bundle.js:1:130097dhttp://lisa.springfield.home/polyfills.b67d9fa4d5aa970cbe0f.bundle.js:1:118485ghttp://lisa.springfield.home/polyfills.b67d9fa4d5aa970cbe0f.bundle.js:1:118720