build: Remove ulimit from build.sh

Previous "reasonable resource limits" cause test failures with Go 1.9.
They were added to protect the previous generation of the build server
and no longer needed.

Fixes issue #4653.

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4656

build.sh

@@ -48,9 +48,6 @@ case "${1:-default}" in
 		;;
 
 	test)
-		ulimit -t 600 &>/dev/null || true
-		ulimit -d 512000 &>/dev/null || true
-		ulimit -m 512000 &>/dev/null || true
 		LOGGER_DISCARD=1 build test
 		;;
 
@@ -94,9 +91,6 @@ case "${1:-default}" in
 		;;
 
 	test-xunit)
-		ulimit -t 600 &>/dev/null || true
-		ulimit -d 512000 &>/dev/null || true
-		ulimit -m 512000 &>/dev/null || true
 
 		(GOPATH="$(pwd)/Godeps/_workspace:$GOPATH" go test -v -race ./lib/... ./cmd/... || true) > tests.out
 		go2xunit -output tests.xml -fail < tests.out