Fix a typo in the JDBC query

On line 3686, the select searches for FKTABLE_SCHEM. The line previously said FKTABLE_SCHEMA (adding an extra a), which would not find the correct column.
merge louisrli: Fix a typo in the JDBC getImportedExportedKeys query

Merge pull request #27 from louisrli/sql-layer-adapter-jdbc/patch-1
https://github.com/FoundationDB/sql-layer-adapter-jdbc/pull/27