curl: Fix build with wolfssl

Backport a commit from upstream curl to fix a problem in configure with
wolfssl.

checking size of time_t... configure: error: cannot determine a size for time_t

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

package/network/utils/curl/patches/100-configure-fix-pkg-config-detecting-wolfssl.patch

@@ -0,0 +1,31 @@
+From 510d98157f21dee5793c4e975fde3317b6139267 Mon Sep 17 00:00:00 2001
+From: Daniel Stenberg <daniel@haxx.se>
+Date: Mon, 24 Aug 2020 16:28:34 +0200
+Subject: [PATCH] configure: fix pkg-config detecting wolfssl
+
+When amending the include path with "/wolfssl", this now properly strips
+off all whitespace from the path variable! Previously this would lead to
+pkg-config builds creating bad command lines.
+
+Closes #5848
+---
+ configure.ac | 8 ++++++--
+ 1 file changed, 6 insertions(+), 2 deletions(-)
+
+--- a/configure.ac
++++ b/configure.ac
+@@ -2474,8 +2474,12 @@ if test -z "$ssl_backends" -o "x$OPT_WOL
+             AC_DEFINE(HAVE_WOLFSSL_DES_ECB_ENCRYPT, 1,
+                       [if you have wolfSSL_DES_ecb_encrypt])
+             if test -n "$addcflags"; then
+-              CPPFLAGS="$addcflags/wolfssl $CPPFLAGS"
+-              AC_MSG_NOTICE([Add $addcflags/wolfssl to CPPFLAGS])
++              dnl use a for loop to strip off whitespace
++              for f in $addcflags; do
++                CPPFLAGS="$f/wolfssl $CPPFLAGS"
++                AC_MSG_NOTICE([Add $f/wolfssl to CPPFLAGS])
++                break
++              done
+             else
+               dnl user didn't give a path, so guess/hope they installed wolfssl
+               dnl headers to system default location