Update unique-paths.py

Author: kamyu104

Python/unique-paths.py

@@ -21,7 +21,7 @@ def nCr(n, r):  # Time: O(n), Space: O(1)
 
 
 # Time:  O(m * n)
-# Space: O(m + n)
+# Space: O(min(m, n))
 class Solution2(object):
     def uniquePaths(self, m, n):
         """