Fixed a typo in definition 3.43

Hey again Lucas
I found another one. Convergence does in fact not imply absolute convergence.
In the handwitten notes it's correct, Analysis-INFK-week7 Page 13/25 of the Document or Page 113 in the Professors count.
I hope I didn't create any chaos when pulling from upstream (your Repo), merging locally and then pushing back to my repo on Github. If I did please let me know.
Have a nice day.
Joel