fix(CertificatePolicy): replace v-model:value with v-model on NcTextField

NcTextField in @nextcloud/vue v9 (Vue 3) binds via modelValue, not a
prop named `value`. Replace v-model:value="OID" with v-model="OID"
so the OID field is correctly two-way bound.

Signed-off-by: Vitor Mattos <1079143+vitormattos@users.noreply.github.com>

Author: vitormattos

src/views/Settings/CertificatePolicy.vue

@@ -6,7 +6,7 @@
 <template>
 	<div>
 		<fieldset class="settings-section__row">
-			<NcTextField v-model:value="OID"
+			<NcTextField v-model="OID"
 				:label="t('libresign', 'Certificate Policy OID')"
 				:placeholder="t('libresign', 'Certificate Policy OID')"
 				:spellcheck="false"