Remove GSI information (SOFTWARE-5164)

I left install-gwms-frontend.md alone because that is being handled in #929.

Author: matyasselmeci

docs/data/xrootd/install-client.md

@@ -3,10 +3,6 @@ title: Using XRootD
 Using XRootD 
 =============
 
-!!!bug "EL7 version compatibility"
-    There is an incompatibility with EL7 < 7.5 due to an issue with the `globus-gsi-proxy-core` package
-
-
 XRootD is a high performance data system widely used by several science VOs on OSG to store and to distribute data to
 jobs.
 It can be used to create a data store from distributed data nodes or to serve data to systems using a distributed

docs/data/xrootd/install-storage-element.md

@@ -3,10 +3,6 @@ title: Installing an XRootD Storage Element
 Installing an XRootD Storage Element
 ====================================
 
-!!!bug "EL7 version compatibility"
-    There is an incompatibility with EL7 < 7.5 due to an issue with the `globus-gsi-proxy-core` package
-
-
 [XRootD](http://xrootd.org/) is a hierarchical storage system that can be used in a variety of ways to access data,
 typically distributed among actual storage resources. 
 One way to use XRootD is to have it refer to many data resources at a single site, and another way to use it is to refer

docs/security/tokens/using-tokens.md

@@ -4,7 +4,7 @@ Using Bearer Tokens
 ===================
 
 As part of the [GridFTP and GSI migration](https://opensciencegrid.org/technology/policy/gridftp-gsi-migration/),
-the OSG will be transitioning authentication away from X.509 certificates to the use of bearer tokens such as
+the OSG has transitioned authentication away from X.509 certificates to the use of bearer tokens such as
 [SciTokens](http://scitokens.org/) or [WLCG JWT](https://twiki.cern.ch/twiki/bin/view/LCG/WLCGAuthorizationWG).
 
 Use this document to learn how to request tokens from an OpenID Connect (OIDC) Provider or how to generate a test token