fix ch11-01-writing-tests: remove duplicate paragraph

[0x766F6964]

The paragraph about filtering tests out with matching test names with strings is duplicated, remove one of those paragraphs.

[iampi31415]

I can see what is removed, but where is the repetition?

[0x766F6964]

line 105, below the benchmark tests paragraph

[iampi31415]

Can you simply copy and paste the line that is duplicated ? @0x766F6964

[0x766F6964]

sure, here and here

[iampi31415]

Yes, that's correct. Given that there isn't a diff highlighting the dup is was hard to find by simply reading.

Also, that's not in the upstream book, so updating it won't fix it. I hope they merge it.