[h2] allow jdbch2 adapter to use jdbc-h2 1.4 (fixes #639)

Author: kares

activerecord-jdbch2-adapter/activerecord-jdbch2-adapter.gemspec

@@ -21,5 +21,5 @@ Gem::Specification.new do |gem|
   gem.files = `git ls-files`.split("\n") # assuming . working directory
 
   gem.add_dependency 'activerecord-jdbc-adapter', "~>#{version}"
-  gem.add_dependency 'jdbc-h2', '~> 1.3.0'
+  gem.add_dependency 'jdbc-h2', '~> 1.3'
 end