texi2pod: Make it output a single encoding string

Intermixing =encoding utf-8 in the file can confuse some pod2man
implementations.

doc/texi2pod.pl

@@ -327,13 +327,14 @@ $inf = pop @instack;
 
 die "No filename or title\n" unless defined $fn && defined $tl;
 
+# always use utf8
+print "=encoding utf8\n\n";
+
 $sects{NAME} = "$fn \- $tl\n";
 $sects{FOOTNOTES} .= "=back\n" if exists $sects{FOOTNOTES};
 
 unshift @sects_sequence, "NAME";
 for $sect (@sects_sequence) {
-    # always use utf8
-    print "=encoding utf8\n";
     if(exists $sects{$sect}) {
         $head = $sect;
         $head =~ s/SEEALSO/SEE ALSO/;