test/TEST-15: call daemon-reload in two more places

Sometimes the test would fail there, nondeterministically. I'm not sure why,
but relying on PID1 not caching the file is clearly very brittle. Let's instead
call daemon-reload.

test/units/testsuite-15.sh

@@ -116,6 +116,7 @@ test_basic_dropins () {
 [Service]
 ExecCondition=/bin/echo %n
 EOF
+    systemctl daemon-reload
     check_ok test15-a ExecCondition "/bin/echo test15-a"
     check_ok test15-b ExecCondition "/bin/echo test15-b"
     rm -rf /usr/lib/systemd/system/service.d
@@ -138,6 +139,7 @@ test_hierarchical_dropins () {
 [Service]
 ExecCondition=/bin/echo $dropin
         " > /usr/lib/systemd/system/$dropin/override.conf
+        systemctl daemon-reload
         check_ok a-b-c ExecCondition "/bin/echo $dropin"
     done
     for dropin in service.d a-.service.d a-b-.service.d a-b-c.service.d; do