fix some man page section numbers form programs referenced in the manpages

including dpkg and dselect which are in 1 instead of 8.

doc/apt.ent

@@ -78,7 +78,7 @@
 
 <!ENTITY dpkg "<citerefentry>
     <refentrytitle><command>dpkg</command></refentrytitle>
-    <manvolnum>8</manvolnum>
+    <manvolnum>1</manvolnum>
   </citerefentry>"
 >
 
@@ -96,19 +96,19 @@
 
 <!ENTITY dpkg-scanpackages "<citerefentry>
     <refentrytitle><command>dpkg-scanpackages</command></refentrytitle>
-    <manvolnum>8</manvolnum>
+    <manvolnum>1</manvolnum>
   </citerefentry>"
 >
 
 <!ENTITY dpkg-scansources "<citerefentry>
     <refentrytitle><command>dpkg-scansources</command></refentrytitle>
-    <manvolnum>8</manvolnum>
+    <manvolnum>1</manvolnum>
   </citerefentry>"
 >
 
 <!ENTITY dselect "<citerefentry>
     <refentrytitle><command>dselect</command></refentrytitle>
-    <manvolnum>8</manvolnum>
+    <manvolnum>1</manvolnum>
   </citerefentry>"
 >