[processing] remove console error message when optional otb provider not installed

(cherry picked from commit 8e66330)

Author: nirvn

python/plugins/processing/algs/otb/OTBAlgorithmProvider.py

@@ -60,8 +60,6 @@ def _loadAlgorithms(self):
 
         version = OTBUtils.getInstalledVersion(True)
         if version is None:
-            ProcessingLog.addToLog(ProcessingLog.LOG_ERROR,
-                                   self.tr('Problem with OTB installation: OTB was not found or is not correctly installed'))
             return
 
         folder = OTBUtils.compatibleDescriptionPath(version)