CORDA-2690: Reduce CordApp scanning logging

Only log a line about looking for notary implementations if at least notary implementation is found.

It might be unnecessary and confusing to log when no implementations are found.
Replaced TrustedAuthorityNotaryService with SinglePartyNotaryService in comment

node/src/main/kotlin/net/corda/node/internal/cordapp/JarScanningCordappLoader.kt

@@ -212,12 +212,14 @@ class JarScanningCordappLoader private constructor(private val cordappJarPaths:
     }
 
     private fun findNotaryService(scanResult: RestrictedScanResult): Class<out NotaryService>? {
-        // Note: we search for implementations of both NotaryService and TrustedAuthorityNotaryService as
+        // Note: we search for implementations of both NotaryService and SinglePartyNotaryService as
         // the scanner won't find subclasses deeper down the hierarchy if any intermediate class is not
         // present in the CorDapp.
         val result = scanResult.getClassesWithSuperclass(NotaryService::class) +
                 scanResult.getClassesWithSuperclass(SinglePartyNotaryService::class)
-        logger.info("Found notary service CorDapp implementations: " + result.joinToString(", "))
+        if(!result.isEmpty()) {
+            logger.info("Found notary service CorDapp implementations: " + result.joinToString(", "))
+        }
         return result.firstOrNull()
     }