remove duplicated 'the' from guides doc-base abstract

Reported-By: lintian: spelling-error-in-doc-base-abstract-field
Git-Dch: Ignore

debian/apt-doc.doc-base.guide

@@ -1,7 +1,7 @@
 Document: apt-user-guide
 Title: APT User's Guide
 Author: Jason Gunthorpe
-Abstract: The APT User's Guide provides an overview of how to use the the
+Abstract: The APT User's Guide provides an overview of how to use the
  APT package manager, and provides a detailed look at the apt-get tool.
 Section: Debian