TT#98400 increase acc_backup/trash insert buffer size

With the increased length of src/dst_leg strings, we must also increase
the buffer size for the insert string.

Did I mention that we should really move to dynamic strings here...

Change-Id: I0e77155d36f434055e36124d37bf699179f887b1

medmysql.c

@@ -551,7 +551,7 @@ static void medmysql_buf_escape(MYSQL *m, size_t *buflen, const char *str, char
 int medmysql_insert_records(med_entry_t *records, uint64_t count, const char *table)
 {
     char *sql_buffer = NULL;
-    size_t sql_buffer_size = (count + 1) * 1024; // some extra space for sql overhead
+    size_t sql_buffer_size = (count + 1) * (sizeof(med_entry_t) + 64) + 256;
     size_t buflen = 0;
     int ret = 0, entries = 0;