curl: allow building for multiple architectures again

With the `.netrc` fix, two files are created by a patch. When reusing
the same `srcdir` for multiple architectures, this would cause problems.
So let's delete the files in question if the `.netrc` fix is done via a
separate `.patch` file.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

mingw-w64-curl/PKGBUILD

@@ -90,6 +90,9 @@ prepare() {
     cmp "${startdir}/../mingw-w64-pathtools/pathtools.h" "${srcdir}/pathtools.h"
   } || exit 1
 
+  test ! -f "${srcdir}/netrc-regression-1.patch" ||
+  rm -f tests/data/test2309 tests/libtest/lib2309.c
+
   cd "${srcdir}/${_realname}-${pkgver}"
   cp -fHv "${srcdir}"/pathtools.[ch] lib/