MINOR: samples: Handle the type SMP_T_METH when we duplicate a sample in smp_dup

First, the type SMP_T_METH was not handled by smp_dup function. It was never
called with this kind of samples, so it's not really a problem. But, this could
be useful in future.

For all known HTTP methods (GET, POST...), there is no extra space allocated for
a sample of type SMP_T_METH. But for unkown methods, it uses a chunk. So, like
for strings, we duplicate data, using a trash chunk.
diff --git a/src/sample.c b/src/sample.c
index 20a59be..28a5fcb 100644
--- a/src/sample.c
+++ b/src/sample.c
@@ -658,6 +658,11 @@
 		/* These type are not const. */
 		break;
 
+	case SMP_T_METH:
+		if (smp->data.u.meth.meth != HTTP_METH_OTHER)
+			break;
+		/* Fall through */
+
 	case SMP_T_STR:
 		trash = get_trash_chunk();
 		trash->len = smp->data.u.str.len;
@@ -678,6 +683,7 @@
 		memcpy(trash->str, smp->data.u.str.str, trash->len);
 		smp->data.u.str = *trash;
 		break;
+
 	default:
 		/* Other cases are unexpected. */
 		return 0;