TT#32917 Fix format truncation warning

The variable is a uint8_t and it can hold up to 255 values, so we need
possibly up to 3 digits plus the ending NUL.

Warned-by: gcc-7
Change-Id: I1b0ae3ad141c048ae924b421d2266a8e37a669c5

medmysql.c

@@ -681,8 +681,8 @@ int medmysql_insert_cdrs(cdr_entry_t *entries, uint64_t count, struct medmysql_b
 			return -1;
 
 		cdr_entry_t *e = &(entries[i]);
-		char str_source_clir[2] = "";
-		char str_split[2] = "";
+		char str_source_clir[4] = "";
+		char str_split[4] = "";
 		char str_init_time[32] = "";
 		char str_start_time[32] = "";
 		char str_duration[32] = "";