Fix cqlsh xrefs (#39)

Author: aimurphy

in-progress/managing.adoc

@@ -2997,7 +2997,7 @@ SELECT * FROM users;
 
 [TIP]
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-You can also execute a CQL file using the `xref:astra@cql:reference:cqlsh-commands/source.adoc[]` CQL command:
+You can also execute a CQL file using the `xref:astra@cql:cqlsh:cqlsh-commands/source.adoc[]` CQL command:
 
 [source,bash,subs="+quotes"]
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