Fix this issue:

src/tcptable.c:484:140: warning: ‘%s’ directive output may be truncated writing up to 63 bytes into a region of size between 0 and 225 [-Wformat-truncation=]

--- a/src/tcptable.c
+++ b/src/tcptable.c
@@ -22,7 +22,7 @@
 #include "hostmon.h"
 #include "sockaddr.h"
 
-#define MSGSTRING_MAX	320
+#define MSGSTRING_MAX	640
 
 unsigned int bmaxy = 0;
 unsigned int imaxy = 0;