Don't try to push the coverity branch on nightlies

This is handled by the internal CI for now.

Signed-off-by: Bence Szépkúti <bence.szepkuti@arm.com>
Change-Id: Ieee2c11573bc20342b3e0b4bf0ed59eeb7452ff6
diff --git a/mbed-tls-nightly-tests.yaml b/mbed-tls-nightly-tests.yaml
index c3f5524..ef31d25 100644
--- a/mbed-tls-nightly-tests.yaml
+++ b/mbed-tls-nightly-tests.yaml
@@ -100,7 +100,7 @@
         name: TEST_FAIL_EMAIL_ADDRESS
         trim: 'false'
     - bool:
-        default: true
+        default: false
         description: Push head to coverity branch, triggering a scan (development only)
         name: PUSH_COVERITY
     pipeline-scm: