[source] build: remove @ as it's causing an error

[LEDE Commits]

jow pushed a commit to source.git, branch lede-17.01:
https://git.lede-project.org/5beb0abc83ecc5d95365c357f6d9fc367d590130

commit 5beb0abc83ecc5d95365c357f6d9fc367d590130
Author: Philip Prindeville <philipp at redfish-solutions.com>
AuthorDate: Tue Sep 19 15:17:09 2017 -0600

    build: remove @ as it's causing an error
    
    Since $(DownloadMethod/unknown) is being invoked in the expansion of
    $(call locked ...) anyway, you can't have an @ because the shell
    doesn't know what to do with it.
    
    Signed-off-by: Philip Prindeville <philipp at redfish-solutions.com>
    (cherry picked from commit 76ba01a39216b8460846808b2fc10d5ee230a324)
---
 include/download.mk | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/download.mk b/include/download.mk
index 82a3dd2..0a25641 100644
--- a/include/download.mk
+++ b/include/download.mk
@@ -103,7 +103,7 @@ hash_var = $(if $(filter-out x,$(1)),MD5SUM,HASH)
 endif
 
 define DownloadMethod/unknown
-	@echo "ERROR: No download method available"; false
+	echo "ERROR: No download method available"; false
 endef
 
 define DownloadMethod/default