Findtdaq.cmake Fix, master branch (2019.11.07.)

Unfortunately I managed to make a typo in !565 (merged). This is to fix that.

At the same time I should really come up with a way for testing for these sort of issues in the CI...

AE Build SUCCESS
Build logfiles are available at Jenkins [AE-MERGE-REQUEST-CC7 #110]

mentioned in commit 64fccba1

merged