Remove reference to ability to use port/username (#5143)

* Remove reference to ability to use port/username

Port and username options do not work in current gpssh release.

* Removed example

* Added missing space

gpdb-doc/dita/utility_guide/admin_utilities/gpssh.xml

@@ -82,12 +82,8 @@
                 <plentry>
                     <pt>-f <varname>hostfile_gpssh</varname></pt>
                     <pd>Specifies the name of a file that contains a list of hosts that will
-                        participate in this SSH session. The host name is required, and you can
-                        optionally specify an alternate user name and/or SSH port number per host.
-                        The syntax of the host file is one host per line as follows:</pd>
-                    <pd>
-                        <codeblock>[<varname>username</varname>@]<varname>hostname</varname>[:<varname>ssh_port</varname>]</codeblock>
-                    </pd>
+                        participate in this SSH session. The syntax of the host file is one host
+                        per line.</pd>
                 </plentry>
                 <plentry>
                     <pt>-h <varname>hostname</varname></pt>