Fix Polish translation (#497)

mat9117

2019-04-14 a9b10cc4b10110a9c54bd03ac07eea3151b10ede

 technic/machines/power_monitor.lua

@@ -55,7 +55,7 @@
         local demand = sw_meta:get_int("demand")
         meta:set_string("infotext",
               S("Power Monitor. Supply: @1 Demand: @2",
               technic.pretty_num(supply), technic.pretty_num(demand)))
               technic.EU_string(supply), technic.EU_string(demand)))
      else
         meta:set_string("infotext",S("Power Monitor Has No Network"))
      end