fix splitting long messages for python 3

Author: Kirill Kirsanov

smpplib/gsm.py

@@ -60,9 +60,11 @@ def make_parts(text):
         parts = []
         ipart = 1
         uid = random.randint(0, 255)
+        print(starts,"asd")
         for start in starts:
-            parts.append(''.join(('\x05\x00\x03', chr(uid),
-                                  chr(len(starts)), chr(ipart),
+
+            parts.append(b''.join((b'\x05\x00\x03', bytes([uid]),
+                                   bytes([len(starts)]), bytes([ipart]),
                                   encode(text[start:start + partsize]))))
             ipart += 1
     else: