[3.6] bpo-32028: Fix suggestions for indented print statements (GH-5249)

[3.6] bpo-32028: Fix suggestions for indented print statements (GH-5249)

The suggested replacement for print statements previously failed to account
for leading whitespace and hence could end up including unwanted text in
the proposed call to the print builtin.

Patch by Sanyam Khurana.
(cherry picked from commit d57f26c753dce61f72b52b96db3a3253d9f2fc3e)