Update .gitignore to ignore SQLite3 databases for parallel testing (#35030).

git-svn-id: http://svn.redmine.org/redmine/trunk@20929 e93f8b46-1217-0410-a6f0-8f06a7374b81

.gitignore

@@ -14,6 +14,7 @@
 /coverage
 /db/*.db
 /db/*.sqlite3
+/db/*.sqlite3-*
 /db/schema.rb
 /files/*
 /lib/redmine/scm/adapters/mercurial/redminehelper.pyc