Add missing space

Author: eregon

spec/ruby/core/string/index_spec.rb

@@ -146,7 +146,7 @@
 
   it "returns the character index after offset" do
     "われわれ".index("わ", 1).should == 2
-    "ありがとうありがとう".index("が",3).should == 7
+    "ありがとうありがとう".index("が", 3).should == 7
   end
 
   it "returns the character index after a partial first match" do