Correct mistake with library version numbering (esp8266#5981)

dok-net · earlephilhower · commit 3cb2ec4ed0f1 · 2019-04-12T08:20:56.000-07:00
Now version 5.0.3 - also available via Arduino library manager now (eps8266, esp32).
diff --git a/libraries/SoftwareSerial b/libraries/SoftwareSerial
@@ -1 +1 @@
-Subproject commit b178c0ff023ff87a4754636b624a6d18e6036a07
+Subproject commit b330eba900d9f69b0c2310ba36192d0d14354510
