Fix compilation on DMD < 2.070.x.

Author: s-ludwig

deimos/openssl/bio.d

@@ -78,7 +78,10 @@ version(OPENSSL_NO_SCTP) {} else {
 version (Posix) {
 	import core.sys.posix.netdb;
 } else version (Windows) {
-	import core.sys.windows.winsock2;
+	static if (__VERSION__ >= 2070)
+		import core.sys.windows.winsock2;
+	else
+		import std.c.windows.winsock;
 } else version (Win64) {
 	import core.sys.windows.winsock2;
 }

deimos/openssl/dtls1.d

@@ -73,7 +73,10 @@ public import deimos.openssl.pqueue;
 // #endif
 version (Windows) {
 /* Needed for timeval */
-import core.sys.windows.winsock2;
+static if (__VERSION__ >= 2070)
+	import core.sys.windows.winsock2;
+else
+	import std.c.windows.winsock;
 // #elif defined(OPENSSL_SYS_NETWARE) && !defined(_WINSOCK2API_)
 // #include <sys/timeval.h>
 // #else