Corrected two typos

Line  : html>`_ or documentation.  ---> should be 'html>`_ for documentation.' adde 'f'  to 'or'

Line 473 :   A test on will ensure that this file --->  the word 'on' removed

(cherry picked from commit 5f6b083)

Author: DiGro

docs/developers_guide/codingstandards.rst

@@ -259,7 +259,7 @@ As soon as a SIP file is added to one of the source file
 :source:`gui_auto.sip <python/gui/gui_auto.sip>` or
 :source:`analysis_auto.sip <python/analysis/analysis_auto.sip>`),
 it will be considered as generated automatically.
-A test on will ensure that this file is up to date with its corresponding header.
+A test will ensure that this file is up to date with its corresponding header.
 
 To force recreation of SIP files, :source:`sipify_all.sh <scripts/sipify_all.sh>`
 shall be executed.