spice-protocol: update to 0.14.3

Major changes in 0.14.3
=======================
* Add VD_AGENT_CLIPBOARD_FILE_LIST to support copy/paste of files with
  WebDAV support
* Add support for side mouse buttons
* Add a MonitorsMM field to VDAgentMonitorsConfig allowing to pass
  physical monitor dimension

Major changes in 0.14.2
=======================
* Removed Autoconf support, only Meson is available
* Removed foreign-menu and controller interfaces
* Deprecated CELT support
* Generate MingW packages building the RPM
* Allows for the agent to pass back a more specific error to the client
* Add quality indicators messages

Major changes in 0.14.1
=======================
* This is the last release with:
  * Autotools: Meson is now the only supported
  * foreign_menu_prot.h: Deprecated in this release
  * controller_prot.h: Deprecated in this release
* Add VD_AGENT_CAP_CLIPBOARD_NO_RELEASE_ON_REGRAB
* Add VD_AGENT_CAP_CLIPBOARD_GRAB_SERIAL
* Add SPICE_MSGC_MAIN_QUALITY_INDICATOR enum
* Add STREAM_TYPE_QUALITY_INDICATOR message
* Remove deprecated vdi_dev.h interface
* Remove deprecated VD_AGENT_CLIPBOARD_MAX_SIZE_DEFAULT
* Remove deprecated VD_AGENT_CLIPBOARD_MAX_SIZE_ENV
* Remove unused SPICE_GNUC_ macros
* qxl_dev: QXLReleaseInfo alignment fix
* Some documentation added in vd_agentd.h
* Now shipping a rpm spec file to easy deployment and testing

(maya)