[CI-Examples] Add Nginx test data files to the manifest

Commit aef087f "[LibOS] Move trusted and allowed files logic to LibOS"
incorrectly modified Makefile of the Nginx example. The test data files
(automatically generated by Makefile and put under Nginx install dir
`install/html/random`) got generated after the Gramine manifest
expansion. This led to those test files not being added as
`sgx.trusted_files` to the manifest, and Nginx server could not retrieve
them and thus returned error code 403 ("Forbidden"). The fix is simple:
move the `$TEST_DATA` variable before the `nginx.manifest` target (which
already has `$TEST_DATA` as its dependency).

This bug was not detected by our CI because the Nginx test uses `wrk`
which ignores error code 403 and happily counts this error response
towards its total stats. This needs to be fixed in a separate commit.

Signed-off-by: Vasanth Nagaraja <vasanth.k.nagaraja@intel.com>

CI-Examples/nginx/Makefile

@@ -17,6 +17,18 @@ LISTEN_HOST ?= 127.0.0.1
 LISTEN_PORT ?= 8002
 LISTEN_SSL_PORT ?= 8444
 
+# HTTP docs: Generating random HTML files in $(INSTALL_DIR)/html/random
+RANDOM_DIR = $(INSTALL_DIR)/html/random
+RANDOM_FILES = \
+ $(foreach n,1 2 3 4 5 6 7 8 9 10,2K.$n.html) \
+ $(foreach n,1 2 3 4 5,10K.$n.html) \
+ $(foreach n,1 2 3 4 5,100K.$n.html) \
+ $(foreach n,1 2 3,1M.$n.html) \
+ $(foreach n,1 2 3,10M.$n.html) \
+ $(foreach n,1 2 3,100.$n.html)
+
+TEST_DATA = $(addprefix $(RANDOM_DIR)/,$(RANDOM_FILES))
+
 ifeq ($(DEBUG),1)
 GRAMINE_LOG_LEVEL = debug
 else
@@ -82,18 +94,6 @@ $(INSTALL_DIR)/conf/nginx-gramine.conf: nginx-gramine.conf.template $(INSTALL_DI
  -e 's|$$(LISTEN_HOST)|'"$(LISTEN_HOST)"'|g' \
  $< > $@
 
-# HTTP docs: Generating random HTML files in $(INSTALL_DIR)/html/random
-RANDOM_DIR = $(INSTALL_DIR)/html/random
-RANDOM_FILES = \
- $(foreach n,1 2 3 4 5 6 7 8 9 10,2K.$n.html) \
- $(foreach n,1 2 3 4 5,10K.$n.html) \
- $(foreach n,1 2 3 4 5,100K.$n.html) \
- $(foreach n,1 2 3,1M.$n.html) \
- $(foreach n,1 2 3,10M.$n.html) \
- $(foreach n,1 2 3,100.$n.html)
-
-TEST_DATA = $(addprefix $(RANDOM_DIR)/,$(RANDOM_FILES))
-
 # We need to first build and install nginx, otherwise nginx' makefiles think that they already
 # filled $(INSTALL_DIR)/html and skip copying installation files.
 $(RANDOM_DIR)/%.html: $(INSTALL_DIR)/sbin/nginx