Only override sysconfdir and mandir when prefix=/usr

(closes issue #13093)
 Reported by: pabelanger


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@134536 65c4cc65-6c06-0410-ace0-fbb531ad65f3

configure

@@ -1,5 +1,5 @@
 #! /bin/sh
-# From configure.ac Revision: 132641 .
+# From configure.ac Revision: 132704 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.61 for asterisk 1.4.
 #
@@ -3961,11 +3961,13 @@ case "${host_os}" in
      ;;
      *)
      ac_default_prefix=/usr
-     if test ${sysconfdir} = '${prefix}/etc'; then
-        sysconfdir=/etc
-     fi
-     if test ${mandir} = '${prefix}/man'; then
-        mandir=/usr/share/man
+     if test ${prefix} = '/usr'; then
+        if test ${sysconfdir} = '${prefix}/etc'; then
+           sysconfdir=/etc
+        fi
+        if test ${mandir} = '${prefix}/man'; then
+           mandir=/usr/share/man
+        fi
      fi
      ;;
 esac