transport: move the cert type enum to types.h

This should make the mingw compiler happy.

include/git2/transport.h

@@ -21,22 +21,6 @@
 GIT_BEGIN_DECL
 
 /**
- * Type of host certificate structure that is passed to the check callback
- */
-typedef enum git_cert_t {
-        /**
-         * The `data` argument to the callback will be a pointer to
-         * the DER-encoded data.
-         */
-	GIT_CERT_X509,
-        /**
-         * The `data` argument to the callback will be a pointer to a
-         * `git_cert_hostkey` structure.
-         */
-	GIT_CERT_HOSTKEY_LIBSSH2,
-} git_cert_t;
-
-/**
  * Hostkey information taken from libssh2
  */
 typedef struct {

include/git2/types.h

@@ -254,7 +254,22 @@ typedef int (*git_transfer_progress_cb)(const git_transfer_progress *stats, void
 typedef int (*git_transport_message_cb)(const char *str, int len, void *payload);
 
 
-typedef enum git_cert_t git_cert_t;
+
+/**
+ * Type of host certificate structure that is passed to the check callback
+ */
+typedef enum git_cert_t {
+        /**
+         * The `data` argument to the callback will be a pointer to
+         * the DER-encoded data.
+         */
+	GIT_CERT_X509,
+        /**
+         * The `data` argument to the callback will be a pointer to a
+         * `git_cert_hostkey` structure.
+         */
+	GIT_CERT_HOSTKEY_LIBSSH2,
+} git_cert_t;
 
 /**
  * Callback for the user's custom certificate checks.