BUG: Fix incorrect assumptions about attached SQLite databases

[cpcloud]

No description provided.

[xmnlab]

@cpcloud maybe you could try openjdk-8-jre to openjdk-11-jre on Dockerfile.dev

[xmnlab]

@cpcloud LGTM! thanks for working on that!

[codecov]

Codecov Report

Merging #1937 into master will decrease coverage by 1.84%.
The diff coverage is 97.61%.

@@            Coverage Diff             @@
##           master    #1937      +/-   ##
==========================================
- Coverage   87.46%   85.62%   -1.85%     
==========================================
  Files          89       89              
  Lines       16405    16419      +14     
  Branches     2093     2094       +1     
==========================================
- Hits        14349    14059     -290     
- Misses       1660     1958     +298     
- Partials      396      402       +6

Impacted Files	Coverage Δ
ibis/sql/alchemy.py	92.28% <100%> (-0.35%)	⬇️
ibis/sql/sqlite/client.py	92.25% <100%> (+0.42%)	⬆️
ibis/sql/postgres/client.py	80.95% <80%> (ø)	⬆️
ibis/bigquery/client.py	41.1% <0%> (-53.39%)	⬇️
ibis/bigquery/compiler.py	59.92% <0%> (-37.5%)	⬇️
ibis/bigquery/udf/api.py	80.48% <0%> (-14.64%)	⬇️
ibis/sql/mysql/client.py	63.29% <0%> (-10.13%)	⬇️
ibis/impala/compiler.py	91.23% <0%> (-5.2%)	⬇️
ibis/pandas/dispatch.py	95.45% <0%> (-4.55%)	⬇️
ibis/pandas/client.py	85.54% <0%> (-3.47%)	⬇️
... and 8 more

[cpcloud]

This is passing here: https://cpcloud.visualstudio.com/ibis/_build/results?buildId=717 so I'm going to merge.