fix fi overflow panic because of multi 'in values' in query text

[zanjie]

the real reason that fi overflow cause index out of range panic is the length of variable f slice need increament when in values length in quota is less than 2

sql: select col1 from tb1 where cond1 in(1) and cond2 in(2);
Fingerprint(sql) got panic: index out of range

after fix

[codecov]

Codecov Report

Merging #58 (d549e74) into master (3e7f9d3) will decrease coverage by 0.18%.
The diff coverage is 100.00%.

❗ Current head d549e74 differs from pull request most recent head 79e0df8. Consider uploading reports for the commit 79e0df8 to get more accurate results

@@            Coverage Diff             @@
##           master      #58      +/-   ##
==========================================
- Coverage   67.25%   67.07%   -0.19%     
==========================================
  Files           7        7              
  Lines        1408     1400       -8     
==========================================
- Hits          947      939       -8     
  Misses        349      349              
  Partials      112      112              

Impacted Files	Coverage Δ
query/query.go	65.97% <100.00%> (+0.17%)	⬆️
log/slow/parser.go	70.80% <0.00%> (-1.13%)	⬇️

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