entry may be a token as well, which we don't want to release (only refilling should do that). Found by EQC:

```
Shrinking....................(20 times)
[{set,{var,1},{call,bg_manager_eqc,set_token_rate,['E',1]}},
 {set,{var,2},{call,bg_manager_eqc,start_process,[]}},
 {set,{var,3},{call,bg_manager_eqc,set_concurrency_limit,[a,1,false]}},
 {set,{var,4},{call,bg_manager_eqc,get_lock,[a,{var,2},[]]}},
 {set,{var,7},{call,bg_manager_eqc,get_token,['E',{var,2}]}},
 {set,{var,8},{call,bg_manager_eqc,stop_process,[{var,2}]}},
 {set,{var,18},{call,bg_manager_eqc,crash,[]}},
 {set,{var,19},{call,bg_manager_eqc,revive,[]}},
 {set,{var,23},{call,bg_manager_eqc,get_token,['E']}}]


Final State:
---------------
alive = true
procs = [{<0.16363.7>,not_running}]
limits = [{a,1}]
locks = [{a,[{#Ref<0.0.5.122064>,<0.16363.7>,[],released}]}]
counts = [{'E',1}]
tokens = [{'E',1}]
---------------


background_mgr_table:
---------------
[{{given,'E'},
  {resource_entry,'E',token,<0.16360.7>,[],undefined,#Ref<0.0.5.122073>,
                  given}},
 {{info,'E'},{resource_info,token,{4294967,1},true}},
 {{info,a},{resource_info,lock,1,true}}]
---------------

bg_manager_eqc:set_token_rate('E', 1) -> 0
bg_manager_eqc:start_process() -> <0.16363.7>
bg_manager_eqc:set_concurrency_limit(a, 1, false) -> 0
bg_manager_eqc:get_lock(a, <0.16363.7>, []) -> #Ref<0.0.5.122064>
bg_manager_eqc:get_token('E', <0.16363.7>) -> ok
bg_manager_eqc:stop_process(<0.16363.7>) -> ok
bg_manager_eqc:crash() -> ok
bg_manager_eqc:revive() -> true
bg_manager_eqc:get_token('E') -> ok

Reason: {postcondition, {1, 'not <', 1}}
```