libcamera: ipa_manager: Fix build without openssl

Since commit bedef55d95 ("libcamera: pub_key: Gracefully handle failures
to load public key") the build will fail if openssl is not found on the
host system.

Use the existing HAVE_IPA_PUBKEY define to avoid accessing pubKey_ which
does not exist when building without openssl.

Signed-off-by: Matthias Fend <matthias.fend@emfend.at>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>

src/libcamera/ipa_manager.cpp

@@ -109,8 +109,10 @@ IPAManager::IPAManager()
 		LOG(IPAManager, Fatal)
 			<< "Multiple IPAManager objects are not allowed";
 
+#if HAVE_IPA_PUBKEY
 	if (!pubKey_.isValid())
 		LOG(IPAManager, Warning) << "Public key not valid";
+#endif
 
 	unsigned int ipaCount = 0;