Restore the NULL-SHA ciphersuite. (Alas.)

Change-Id: Ia5398f3b86a13fb20dba053f730b51a0e57b9aa4
Reviewed-on: https://boringssl-review.googlesource.com/5791
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/ssl/test/runner/conn.go b/ssl/test/runner/conn.go
index b23a104..ed016e0 100644
--- a/ssl/test/runner/conn.go
+++ b/ssl/test/runner/conn.go
@@ -416,6 +416,8 @@
 			//
 			// However, our behavior matches OpenSSL, so we leak
 			// only as much as they do.
+		case nullCipher:
+			break
 		default:
 			panic("unknown cipher type")
 		}
@@ -521,6 +523,8 @@
 			b.resize(recordHeaderLen + explicitIVLen + len(prefix) + len(finalBlock))
 			c.CryptBlocks(b.data[recordHeaderLen+explicitIVLen:], prefix)
 			c.CryptBlocks(b.data[recordHeaderLen+explicitIVLen+len(prefix):], finalBlock)
+		case nullCipher:
+			break
 		default:
 			panic("unknown cipher type")
 		}