`removeReaction!` etc. doesn't update all fields in a `CoreModel`

[htpusa]

using COBREXA
model = load_model(CoreModel,"test/downloaded/e_coli_core.xml")
removeReaction!(model,1)
n_reactions(model) # 94
length(model.grrs) # 95

Only some of the fields are updated so, for example, the gene associations end up not matching anymore.

[exaexa]

ah this. We added grrs later so this is an avoidable but kinda expected bug. Thanks for report