dev-cpp/cpp-httplib: fix 32-bit condition in src_test

README says that 32-bit arches aren't supported, so we're going to drop
keywords there + mask, but let's fix this while here.

Bug: https://bugs.gentoo.org/973312
Signed-off-by: Sam James <sam@gentoo.org>

dev-cpp/cpp-httplib/cpp-httplib-0.38.0.ebuild

@@ -77,9 +77,9 @@ src_configure() {
 }
 
 multilib_src_test() {
-	if [[ ${ABI} == x86 ]]; then
+	if [[ $(tc-get-ptr-size) == 4 ]] ; then
 		ewarn "Upstream no longer supports 32 bits:"
-		ewarn https://github.com/yhirose/cpp-httplib/issues/2148
+		ewarn "https://github.com/yhirose/cpp-httplib/issues/2148"
 		return
 	fi