Fix wrong prefix name for release file

Author: mblaschke

Makefile

@@ -7,7 +7,7 @@ ALL = \
 	$(foreach suffix,linux osx win.exe,\
 		build/gr-$(arch)-$(suffix))) \
 	$(foreach arch,arm arm64,\
-		build/go-crond-$(arch)-linux)
+		build/gr-$(arch)-linux)
 
 all: test build
 
@@ -32,11 +32,11 @@ build/gr-32-%: $(SOURCE)
 	@mkdir -p $(@D)
 	CGO_ENABLED=0 GOOS=$(firstword $($*) $*) GOARCH=386 $(GOBUILD) -o $@
 
-build/go-crond-arm-linux: $(SOURCE)
+build/gr-arm-linux: $(SOURCE)
 	@mkdir -p $(@D)
 	CGO_ENABLED=0 GOOS=linux GOARCH=arm GOARM=6 $(GOBUILD) -o $@
 
-build/go-crond-arm64-linux: $(SOURCE)
+build/gr-arm64-linux: $(SOURCE)
 	@mkdir -p $(@D)
 	CGO_ENABLED=0 GOOS=linux GOARCH=arm64 $(GOBUILD) -o $@