Remove extra "or" from sentence

Exploit-Ranking.md

@@ -21,7 +21,7 @@ The ranking values are one of the following, in descending order of reliability:
 | **GoodRanking**      | The exploit has a default target and it is the "common case" for this type of software (English, Windows 7 for a desktop app, 2012 for server, etc). Exploit does not auto-detect the target. |
 | **NormalRanking**    | The exploit is otherwise reliable, but depends on a specific version that is not the "common case" for this type of software and can't (or doesn't) reliably autodetect. |
 | **AverageRanking**   | The exploit is generally unreliable or difficult to exploit, but has a success rate of 50% or more for common platforms. |
-| **LowRanking**       | The exploit is nearly impossible to exploit (or under 50% success rate) for common platforms. |
+| **LowRanking**       | The exploit is nearly impossible to exploit (under 50% success rate) for common platforms. |
 | **ManualRanking**    | The exploit is unstable or difficult to exploit and is basically a DoS (15% success rate or lower). This ranking is also used when the module has no use unless specifically configured by the user (e.g.: [exploit/unix/webapp/php_eval](https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/unix/webapp/php_eval.rb)). |
 
 The ranking value is available the module Class object as well as instances: