Wrap the check for broken versions of SQLite in a compile time test.

Bert pointed out that the sqlite3_test_control() API is not stable,
so without this we might not build against future SQLite versions.
This removes some of the checking but it's doubtful that people will
move from say 3.9 to 3.8.3.

* subversion/libsvn_subr/sqlite.c
  (svn_sqlite__open): Only do the test for 3.8 not 3.7 or 3.9.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1567392 13f79535-47bb-0310-9956-ffa450edef68