openladp: test rebuild

CPPFLAGS was removed to fix a compiler error:
https://sourceforge.net/p/msys2/discussion/general/thread/90241b3d/

Since we no longer set CPPFLAGS now, make sure everything still works

mingw-w64-openldap/PKGBUILD

@@ -4,7 +4,7 @@ _realname=openldap
 pkgbase=mingw-w64-${_realname}
 pkgname="${MINGW_PACKAGE_PREFIX}-${_realname}"
 pkgver=2.6.8
-pkgrel=1
+pkgrel=2
 pkgdesc="OpenLDAP Software is an open source implementation of the Lightweight Directory Access Protocol (only client) (mingw-w64)"
 arch=('any')
 mingw_arch=('mingw64' 'ucrt64' 'clang64' 'clangarm64')
@@ -66,7 +66,6 @@ build() {
 
   mkdir -p build-${MSYSTEM} && cd build-${MSYSTEM}
 
-  unset CPPFLAGS
   export lt_cv_deplibs_check_method='pass_all'
   CFLAGS+=" -Wno-implicit-int" \
   ../${_realname}-${pkgver}/configure \