Debian: adjusted dpkg-buildflags to include "pie" feature.

Inspired by:
https://lintian.debian.org/tags/hardening-no-pie.html

debian/nginx-module.rules.in

diff --git a/debian/nginx-module.rules.in b/debian/nginx-module.rules.in
index 73538f7..f0ab393 100755
--- a/debian/nginx-module.rules.in
+++ b/debian/nginx-module.rules.in
@@ -1,9 +1,9 @@
 #!/usr/bin/make -f
 
 #export DH_VERBOSE=1
-export DEB_BUILD_MAINT_OPTIONS=hardening=+all,-pie                              
-export DEB_CFLAGS_MAINT_APPEND=-Wp,-D_FORTIFY_SOURCE=2
-DPKG_EXPORT_BUILDFLAGS = 1                                                      
+export DEB_BUILD_MAINT_OPTIONS=hardening=+all
+export DEB_CFLAGS_MAINT_APPEND=-Wp,-D_FORTIFY_SOURCE=2 -fPIC
+DPKG_EXPORT_BUILDFLAGS = 1
 include /usr/share/dpkg/buildflags.mk
 
 BUILDDIR_nginx = $(CURDIR)/debian/build-nginx

debian/nginx.rules.in

diff --git a/debian/nginx.rules.in b/debian/nginx.rules.in
index d08d32b..16f6737 100755
--- a/debian/nginx.rules.in
+++ b/debian/nginx.rules.in
@@ -1,7 +1,7 @@
 #!/usr/bin/make -f
 
 #export DH_VERBOSE=1
-export DEB_BUILD_MAINT_OPTIONS=hardening=+all,-pie
+export DEB_BUILD_MAINT_OPTIONS=hardening=+all
 export DEB_CFLAGS_MAINT_APPEND=-Wp,-D_FORTIFY_SOURCE=2 -fPIC
 export DEB_LDFLAGS_MAINT_APPEND=-Wl,--as-needed -pie
 DPKG_EXPORT_BUILDFLAGS = 1