Change default allocation in xy_strjoin()

helper.h

@@ -171,7 +171,7 @@ xy_2strjoin (const char* str1, const char* str2)
 static char*
 xy_strjoin (unsigned int count, ...)
 {
-  size_t al_fixed = 64;
+  size_t al_fixed = 128;
   char* ret = calloc(1, al_fixed);
   // 已分配次数
   int al_times = 1;