patch 9.0.1023: MS-Windows: dynamic loading of libsodium doesn't work

Problem:    MS-Windows: dynamic loading of libsodium doesn't work.
Solution:   Add "randombytes_random". (Ken Takata, closes #11667)
diff --git a/src/evalfunc.c b/src/evalfunc.c
index 428c4cb..84df6a6 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -8166,8 +8166,8 @@
 	// - reltime() or time()
 	// - XOR with process ID
 #if defined(FEAT_SODIUM)
-	if (sodium_init() >= 0)
-	    *x = randombytes_random();
+	if (crypt_sodium_init() >= 0)
+	    *x = crypt_sodium_randombytes_random();
 	else
 #endif
 	{