Update build.vars

Enable Windows only vars for only Windows builds

Author: TinCanTech

generic/build.vars

@@ -41,7 +41,9 @@ EXTRA_OPENSSL_CONFIG="${EXTRA_OPENSSL_CONFIG:--static-libgcc}" # uncomment if op
 #EXTRA_PKCS11_HELPER_CONFIG
 #EXTRA_OPENVPN_CONFIG
 
-EXTRA_TARGET_CFLAGS="-Wl,--dynamicbase,--nxcompat"
+case "${CHOST}" in
+     *mingw*) EXTRA_TARGET_CFLAGS="-Wl,--dynamicbase,--nxcompat";;
+esac
 
 # You can enable --high-entropy-va for 64-bit builds if you have recent enough
 # mingw-w64