plugin.xml: delete reference to removed iOS lib libNetEq4.a
plugin.xml: delete reference to removed iOS lib libNetEq4.a

see https://github.com/alongubkin/phonertc/issues/52#issuecomment-51659446

De-Lac/phonertc,moukail/phonertc,yogomi/phonertc,kennu/phonertc,egorvinogradov/phonertc,rogervaas/phonertc,MadBelette/phonertc,egorvinogradov/phonertc,alongubkin/phonertc,alongubkin/phonertc,hcxiong/phonertc,yogomi/phonertc,moukail/phonertc,cesterlizi/phonertc,MadBelette/phonertc,erhuabushuo/phonertc,De-Lac/phonertc,rogervaas/phonertc,Ycfx/phonertc,yogomi/phonertc,IgorButirsky/rtc,MartySchmidt/phonertc,Ycfx/phonertc,alongubkin/phonertc,ravisr/phonertc,BetterVoice/phonertc,erhuabushuo/phonertc,eug17/phonertc,MadBelette/phonertc,rogervaas/phonertc,MartySchmidt/phonertc,egorvinogradov/phonertc,eug17/phonertc,noprotocol/phonertc,hcxiong/phonertc,kennu/phonertc,moukail/phonertc,hcxiong/phonertc,moukail/phonertc,rogervaas/phonertc,kennu/phonertc,kennu/phonertc,MartySchmidt/phonertc,eug17/phonertc,MadBelette/phonertc,De-Lac/phonertc,moukail/phonertc,rogervaas/phonertc,Ycfx/phonertc,ravisr/phonertc,hcxiong/phonertc,yogomi/phonertc,noprotocol/phonertc,De-Lac/phonertc,BetterVoice/phonertc,ravisr/phonertc,cesterlizi/phonertc,cesterlizi/phonertc,eug17/phonertc,noprotocol/phonertc,alongubkin/phonertc,ravisr/phonertc,MadBelette/phonertc,erhuabushuo/phonertc,kennu/phonertc,BetterVoice/phonertc,egorvinogradov/phonertc,yogomi/phonertc,cesterlizi/phonertc,IgorButirsky/rtc,Ycfx/phonertc,MartySchmidt/phonertc,eug17/phonertc,erhuabushuo/phonertc,Ycfx/phonertc,erhuabushuo/phonertc,hcxiong/phonertc,egorvinogradov/phonertc,noprotocol/phonertc