Rising interest rates helped boost Hong Kong banks as the city’s economy slowed last year, but heightened uncertainty from an escalating trade war between the United States and China could weigh on their performance in 2019, according to KPMG.Operating profit before impairments at the city’s licensed banks rose 15 per cent to HK$268 billion (US$34 billion) last year, from HK$234 billion in 2017, the accounting giant said. Total revenue at Hong Kong’s lenders increased 11.2 per cent to HK$445…