[Evolution] Build fails due to error: redefinition of typedef 'EMailPartItip'

[Reid Thompson <Reid Thompson ateb com>]

make[5]: Entering directory `/home/rthompso/evo-git-head/obj/evolution/modules/itip-formatter'
  CC     module_itip_formatter_la-e-mail-formatter-itip.lo
  CC     module_itip_formatter_la-e-mail-parser-itip.lo
  CC     module_itip_formatter_la-itip-view.lo
In file included from ../../../../evolution/modules/itip-formatter/e-mail-formatter-itip.c:33:0:
../../../../evolution/modules/itip-formatter/e-mail-part-itip.h:36:31: error: redefinition of typedef 
'EMailPartItip'
../../../../evolution/modules/itip-formatter/itip-view.h:46:31: note: previous declaration of 'EMailPartItip' 
was here
In file included from ../../../../evolution/modules/itip-formatter/e-mail-formatter-itip.c:33:0:
../../../../evolution/modules/itip-formatter/e-mail-part-itip.h:119:31: error: redefinition of typedef 
'EMailPartItip'
../../../../evolution/modules/itip-formatter/e-mail-part-itip.h:36:31: note: previous declaration of 
'EMailPartItip' was here
In file included from ../../../../evolution/modules/itip-formatter/e-mail-parser-itip.c:39:0:
../../../../evolution/modules/itip-formatter/e-mail-part-itip.h:36:31: error: redefinition of typedef 
'EMailPartItip'
../../../../evolution/modules/itip-formatter/itip-view.h:46:31: note: previous declaration of 'EMailPartItip' 
was here
In file included from ../../../../evolution/modules/itip-formatter/e-mail-parser-itip.c:39:0:
../../../../evolution/modules/itip-formatter/e-mail-part-itip.h:119:31: error: redefinition of typedef 
'EMailPartItip'
../../../../evolution/modules/itip-formatter/e-mail-part-itip.h:36:31: note: previous declaration of 
'EMailPartItip' was here
make[5]: *** [module_itip_formatter_la-e-mail-parser-itip.lo] Error 1