Fixed some typos, courtesy of codespell

Main change is the conversion from the British cancelling/-ed to the
American canceling/-ed.

src/libstrongswan/plugins/keychain/keychain_creds.c

@@ -148,7 +148,7 @@ static job_requeue_t monitor_changes(private_keychain_creds_t *this)
 	{
 		this->loop = CFRunLoopGetCurrent();
 
-		/* does not return until cancelled */
+		/* does not return until canceled */
 		CFRunLoopRun();
 
 		this->loop = NULL;

src/libstrongswan/plugins/pkcs11/pkcs11_manager.c

@@ -173,7 +173,7 @@ CALLBACK(dispatch_slot_events, job_requeue_t,
 	rv = entry->lib->f->C_WaitForSlotEvent(0, &slot, NULL);
 	if (rv == CKR_FUNCTION_NOT_SUPPORTED || rv == CKR_NO_EVENT)
 	{
-		DBG1(DBG_CFG, "module '%s' does not support hot-plugging, cancelled",
+		DBG1(DBG_CFG, "module '%s' does not support hot-plugging, canceled",
 			 entry->lib->get_name(entry->lib));
 		return JOB_REQUEUE_NONE;
 	}

src/libstrongswan/plugins/winhttp/winhttp_fetcher.c

@@ -165,7 +165,7 @@ static bool read_result(private_winhttp_fetcher_t *this, HINTERNET request,
 		}
 		if (!this->cb(user, chunk_create(buf, received)))
 		{
-			DBG1(DBG_LIB, "processing response failed or cancelled");
+			DBG1(DBG_LIB, "processing response failed or canceled");
 			return FALSE;
 		}
 	}