Remove leading space from keywords.txt identifier

Each field of keywords.txt is separated by a single true tab. Leading spaces on a keyword identifier causes it to not be recognized by the Arduino IDE. On Arduino IDE 1.6.5 and newer an unrecognized keyword identifier causes the default editor.function.style highlighting to be used (as with KEYWORD2, KEYWORD3).

Reference:
https://github.com/arduino/Arduino/wiki/Arduino-IDE-1.5:-Library-specification#keywords

keywords.txt

@@ -1,14 +1,14 @@
-SBUS  KEYWORD1
+SBUS	KEYWORD1
 
-begin KEYWORD2
-process KEYWORD2
-getChannel  KEYWORD2
-getNormalizedChannel  KEYWORD2
-getFailsafeStatus KEYWORD2
-getFrameLoss  KEYWORD2
-getGoodFrames KEYWORD2
-getLostFrames KEYWORD2
-getDecoderErrorFrames KEYWORD2
+begin	KEYWORD2
+process	KEYWORD2
+getChannel	KEYWORD2
+getNormalizedChannel	KEYWORD2
+getFailsafeStatus	KEYWORD2
+getFrameLoss	KEYWORD2
+getGoodFrames	KEYWORD2
+getLostFrames	KEYWORD2
+getDecoderErrorFrames	KEYWORD2
 
-SBUS_FAILSAFE_INACTIVE LITERAL1
-SBUS_FAILSAFE_ACTIVE LITERAL1
+SBUS_FAILSAFE_INACTIVE	LITERAL1
+SBUS_FAILSAFE_ACTIVE	LITERAL1