libfido2: fix musl builds

srcpkgs/libfido2/template

@@ -14,9 +14,15 @@ checksum=5990f923c9390fe1e6a00ba5d1d1f74030e7344b855e971d9fb7223e70ff3122
 
 CFLAGS="-Wno-type-limits"
 if [ "$XBPS_TARGET_LIBC" = musl ]; then
-	CFLAGS+=" -Wno-overflow"  # ioctl takes int on musl
+	# ioctl takes int on musl
+	CFLAGS+=" -Wno-overflow"
 fi
 
+pre_configure() {
+	vsed -i -e "s;sign-conversion;no-sign-conversion;" \
+		{tools,src,examples}/CMakeLists.txt
+}
+
 post_install() {
 	vlicense LICENSE
 }