build: update waf to version 2.0.6

Change-Id: I9cb1f2dbd01312a0b113dd33a4ca9fae344b087c
diff --git a/.jenkins.d/10-build.sh b/.jenkins.d/10-build.sh
index 08d2d53..9ee5a78 100755
--- a/.jenkins.d/10-build.sh
+++ b/.jenkins.d/10-build.sh
@@ -25,13 +25,13 @@
   sudo env "PATH=$PATH" ./waf --color=yes distclean
 fi
 
-# Configure/build in debug mode with tests and without precompiled headers
+# Configure/build in debug mode with tests
 if [[ $JOB_NAME == *"code-coverage" ]]; then
     COVERAGE="--with-coverage"
 elif [[ -n $BUILD_WITH_ASAN || -z $TRAVIS ]]; then
     ASAN="--with-sanitizer=address"
 fi
-./waf --color=yes configure --debug --with-tests --without-pch $COVERAGE $ASAN
+./waf --color=yes configure --debug --with-tests $COVERAGE $ASAN
 ./waf --color=yes build -j${WAF_JOBS:-1}
 
 # (tests will be run against debug version)