cpu/esp8266: don't disconnect on pbuf full in send
cpu/esp8266: don't disconnect on pbuf full in send

Disconnecting from the AP in the send function if the lwIP packet buffer is exhausted is counterproductive since reconnecting usually fails on heavy network load. A better strategy is to slow down the sending of MAC frames from netif a bit to wait for flushing the buffer in the MAC layer.
mtausig/RIOT,authmillenon/RIOT,mtausig/RIOT,authmillenon/RIOT,rfuentess/RIOT,josephnoir/RIOT,smlng/RIOT,kYc0o/RIOT,josephnoir/RIOT,OTAkeys/RIOT,x3ro/RIOT,A-Paul/RIOT,RIOT-OS/RIOT,rfuentess/RIOT,miri64/RIOT,BytesGalore/RIOT,BytesGalore/RIOT,x3ro/RIOT,miri64/RIOT,x3ro/RIOT,OlegHahm/RIOT,rfuentess/RIOT,yogo1212/RIOT,toonst/RIOT,yogo1212/RIOT,kaspar030/RIOT,josephnoir/RIOT,aeneby/RIOT,kaspar030/RIOT,mfrey/RIOT,jasonatran/RIOT,ant9000/RIOT,smlng/RIOT,basilfx/RIOT,toonst/RIOT,ant9000/RIOT,lazytech-org/RIOT,OlegHahm/RIOT,authmillenon/RIOT,mfrey/RIOT,jasonatran/RIOT,kYc0o/RIOT,A-Paul/RIOT,yogo1212/RIOT,miri64/RIOT,RIOT-OS/RIOT,kaspar030/RIOT,cladmi/RIOT,kYc0o/RIOT,lazytech-org/RIOT,smlng/RIOT,basilfx/RIOT,kaspar030/RIOT,josephnoir/RIOT,A-Paul/RIOT,OTAkeys/RIOT,toonst/RIOT,authmillenon/RIOT,jasonatran/RIOT,x3ro/RIOT,aeneby/RIOT,lazytech-org/RIOT,mfrey/RIOT,OTAkeys/RIOT,josephnoir/RIOT,mfrey/RIOT,toonst/RIOT,cladmi/RIOT,miri64/RIOT,cladmi/RIOT,smlng/RIOT,jasonatran/RIOT,RIOT-OS/RIOT,cladmi/RIOT,rfuentess/RIOT,toonst/RIOT,A-Paul/RIOT,lazytech-org/RIOT,BytesGalore/RIOT,x3ro/RIOT,OlegHahm/RIOT,OTAkeys/RIOT,basilfx/RIOT,mtausig/RIOT,basilfx/RIOT,mfrey/RIOT,ant9000/RIOT,kYc0o/RIOT,yogo1212/RIOT,miri64/RIOT,kYc0o/RIOT,cladmi/RIOT,yogo1212/RIOT,A-Paul/RIOT,aeneby/RIOT,OTAkeys/RIOT,smlng/RIOT,lazytech-org/RIOT,aeneby/RIOT,mtausig/RIOT,rfuentess/RIOT,BytesGalore/RIOT,RIOT-OS/RIOT,ant9000/RIOT,ant9000/RIOT,BytesGalore/RIOT,authmillenon/RIOT,yogo1212/RIOT,jasonatran/RIOT,OlegHahm/RIOT,kaspar030/RIOT,aeneby/RIOT,mtausig/RIOT,RIOT-OS/RIOT,basilfx/RIOT,authmillenon/RIOT,OlegHahm/RIOT