Minor fix to show missing -sources.jar error also in the log (#170)

eclipse-platform/eclipse.platform.releng#126

publish-to-maven-central/publishProject.sh

@@ -111,7 +111,7 @@ do
 	else
 		# If the -sources.jar is missing, and the main jar contains .class files, then we won't be able to promote this to Maven central.
 		if unzip -l ${file} | grep -q -e '.class$'; then 
-			echo "BUILD FAILURE ${file} contains .class files and requires a ${sourcesFile}" | tee >> .log/sources-upload.txt
+			echo "BUILD FAILURE ${file} contains .class files and requires a ${sourcesFile}" | tee -a .log/sources-upload.txt
 		else
 			echo -e "\tMissing ${sourcesFile} but ${file} contains no .class files."
 		fi;