Configure: fixed perl module make rules.

Filename extension used for dynamically loaded perl modules isn't
necessarily ".so" (e.g., it's ".bundle" on Mac OS X).

This fixes "make" after "make" unnecessarily rebuilding perl module.

auto/lib/perl/conf

diff --git a/auto/lib/perl/conf b/auto/lib/perl/conf
index 5ce6c91..2fbaa76 100644
--- a/auto/lib/perl/conf
+++ b/auto/lib/perl/conf
@@ -40,6 +40,8 @@
 
     ngx_perl_ldopts=`$NGX_PERL -MExtUtils::Embed -e ldopts`
 
+    ngx_perl_dlext=`$NGX_PERL -MConfig -e 'print $Config{dlext}'`
+
     if $NGX_PERL -V:usemultiplicity | grep define > /dev/null; then
         have=NGX_HAVE_PERL_MULTIPLICITY . auto/have
         echo " + perl interpreter multiplicity found"
@@ -51,7 +53,7 @@
     fi
 
     CORE_LINK="$CORE_LINK $ngx_perl_ldopts"
-    LINK_DEPS="$LINK_DEPS $NGX_OBJS/src/http/modules/perl/blib/arch/auto/nginx/nginx.so"
+    LINK_DEPS="$LINK_DEPS $NGX_OBJS/src/http/modules/perl/blib/arch/auto/nginx/nginx.$ngx_perl_dlext"
 
     if test -n "$NGX_PERL_MODULES"; then
         have=NGX_PERL_MODULES value="(u_char *) \"$NGX_PERL_MODULES\""

auto/lib/perl/make

diff --git a/auto/lib/perl/make b/auto/lib/perl/make
index dbfc83a..1c8f21c 100644
--- a/auto/lib/perl/make
+++ b/auto/lib/perl/make
@@ -5,7 +5,7 @@
 
 cat << END                                                    >> $NGX_MAKEFILE
 
-$NGX_OBJS/src/http/modules/perl/blib/arch/auto/nginx/nginx.so: \\
+$NGX_OBJS/src/http/modules/perl/blib/arch/auto/nginx/nginx.$ngx_perl_dlext: \\
 		\$(CORE_DEPS) \$(HTTP_DEPS) \\
 		src/http/modules/perl/ngx_http_perl_module.h \\
 		$NGX_OBJS/src/http/modules/perl/Makefile