[BUGFIX] stdWrap numRows fails due to wrong SELECT clause

Exclude aggregate functions count(), sum(), max(),
min(), avg() in if statement inside
tslib_cObj::sanitizeSelectPart().

Change-Id: I5d8cd5f00472b417dad3c8790b1cc75f3cfd473a
Fixes: #34152
Releases: 4.5, 4.6, 4.7, 6.0
Reviewed-on: http://review.typo3.org/9158
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn
Reviewed-by: Alain
Tested-by: Alain
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters
Reviewed-by: Stefan Neufeind
Reviewed-by: Ernesto Baschny
Tested-by: Ernesto Baschny