Fix yum config syntax (#4388)

* Remove leading hyphens
* Remove trailing backslashes

Author: Lennonka

guides/common/modules/proc_upgrading-a-disconnected-project-server.adoc

@@ -83,25 +83,25 @@ $ hammer content-export complete repository \
 [source, none, options="nowrap" subs="attributes"]
 ----
 [{RepoRHEL9BaseOS}]
---name=Red Hat Enterprise Linux 9 for x86_64 - BaseOS (RPMs) \
---metadata_expire=-1 \
---gpgcheck=0 \
---cost=500 \
---baseurl=file:///_Export_Baseos_Location_/content/dist/rhel9/9/x86_64/baseos/os \
+name=Red Hat Enterprise Linux 9 for x86_64 - BaseOS (RPMs)
+metadata_expire=-1
+gpgcheck=0
+cost=500
+baseurl=file:///_Export_Baseos_Location_/content/dist/rhel9/9/x86_64/baseos/os
 [{RepoRHEL9AppStream}]
---name=Red Hat Enterprise Linux 9 for x86_64 - AppStream (RPMs) \
---mediaid=None \
---metadata_expire=-1 \
---gpgcheck=0 \
---cost=500 \
---baseurl=file:///_Export_Appstream_Location_/content/dist/rhel9/9/x86_64/appstream/os \
+name=Red Hat Enterprise Linux 9 for x86_64 - AppStream (RPMs)
+mediaid=None
+metadata_expire=-1
+gpgcheck=0
+cost=500
+baseurl=file:///_Export_Appstream_Location_/content/dist/rhel9/9/x86_64/appstream/os
 [{Project}]
---name={Project} \
---mediaid=None \
---metadata_expire=-1 \
---gpgcheck=0 \
---cost=500 \
---baseurl=file:///_Export_Location_/content/dist/layered/rhel9/x86_64/{project-context}/{ProjectVersion}/os/
+name={Project}
+mediaid=None
+metadata_expire=-1
+gpgcheck=0
+cost=500
+baseurl=file:///_Export_Location_/content/dist/layered/rhel9/x86_64/{project-context}/{ProjectVersion}/os/
 ----
 . Upgrade the {foreman-maintain} utility to its latest version:
 +