Fix footprint associations of library parts

kicad-library/symbols/GY-B11_EP_280.lib

 DEF GY-B11_EP_280 U 0 20 Y Y 1 F N
 F0 "U" -250 450 50 H V C CNN
 F1 "GY-B11_EP_280" 200 450 50 H V C CNN
-F2 "Own_Library:GY-B11_EP_280_SMD" 1500 -450 50 H I C CNN
+F2 "footprints:GY-B11_EP_280_SMD" 1500 -450 50 H I C CNN
 F3 "" -100 -200 50 H I C CNN
 $FPLIST
  *LGA*2.5x2.5mm*P0.65mm*Clockwise*

kicad-library/symbols/NRF24L01_Breakout_SMD.lib

 DEF NRF24L01_Breakout_SMD U 0 40 Y Y 1 F N
 F0 "U" -350 500 50 H V L CNN
 F1 "NRF24L01_Breakout_SMD" 150 500 50 H V L CNN
-F2 "NRF24L01+breakout_SMD:NRF24L01+breakout_SMD" 150 600 50 H I L CIN
+F2 "footprints:NRF24L01+breakout_SMD" 150 600 50 H I L CIN
 F3 "" 0 -100 50 H I C CNN
 $FPLIST
  nRF24L01*Breakout*