Invalidate board and message index cache when deleting topics for good
Invalidate board and message index cache when deleting topics for good

Signed-off-by: emanuele <ac2faa8b943b3fcadaf05ed2541f4eebde440ed7@gmail.com>

joshuaadickerson/Elkarte2,Spuds/Elkarte,interlab/Elkarte,StealthWombat/How-to-fork-an-Elk,elkarte/Elkarte,nwsw/Elkarte,wizardaf/Elkarte,elkarte/Elkarte,Spuds/Elkarte,nwsw/Elkarte,emanuele45/Dialogo,StealthWombat/How-to-fork-an-Elk,StealthWombat/How-to-fork-an-Elk,interlab/Elkarte,joshuaadickerson/Elkarte2,elkarte/Elkarte,Ant59/Elkarte,joshuaadickerson/Elkarte2,emanuele45/Dialogo,wizardaf/Elkarte,StealthWombat/How-to-fork-an-Elk,joshuaadickerson/Elkarte2,wizardaf/Elkarte,Spuds/Elkarte,wizardaf/Elkarte,Ant59/Elkarte,Ant59/Elkarte,nwsw/Elkarte,emanuele45/Dialogo,interlab/Elkarte