Due to the async nature of SYSTEM RELOAD DICTIONARY/DICTIONARIES the
test can fail, if the reload will happen after the dictGet*():
.862801 [ 36 ] {61df55ee-4a17-4bf3-8cfb-9478490393c3} <Debug> executeQuery: (from [::1]:37422) SYSTEM RELOAD DICTIONARY `foo 1234.dict`
.863681 [ 36 ] {cd55d9f9-d176-4b19-bc97-d25575da2d15} <Debug> executeQuery: (from [::1]:37422) SELECT query_count FROM system.dictionaries WHERE (database = 'foo 1234') AND ...
.863678 [ 54 ] {} <Debug> executeQuery: (internal) SELECT `key`, `val` FROM `foo 1234`.`dict_data`;
This is just a hotfix, long-term solution will be to make SYSTEM RELOAD
DICTIONARY syncronous (by adding another command or making already
existing).
Refs: #7916