Remove a reference to Ruby 1.9 in Guides

[ci skip]

Now that Rails requires Ruby >= 2.0 there is no need to document
Ruby 1.9.

1 files changed, 1 insertions, 1 deletions

diff --git a/guides/source/active_support_core_extensions.md b/guides/source/active_support_core_extensions.md
index 616b813817..7b11092f3d 100644
--- a/guides/source/active_support_core_extensions.md
+++ b/guides/source/active_support_core_extensions.md
@@ -1447,7 +1447,7 @@ Returns the substring of the string starting at position `position`:
 "hello".from(0)  # => "hello"
 "hello".from(2)  # => "llo"
 "hello".from(-2) # => "lo"
-"hello".from(10) # => "" if < 1.9, nil in 1.9
+"hello".from(10) # => nil
 ```
 
 NOTE: Defined in `active_support/core_ext/string/access.rb`.