fix(Servo): remove warnings raised by arduino-lint

WARNING: library.properties maintainer value Arduino <info@arduino.cc> starts with "Arduino". 3rd party libraries are
         not maintained by Arduino. (Rule LP027)
WARNING: library.properties maintainer value Arduino <info@arduino.cc> contains "Arduino". 3rd party libraries are not
         maintained by Arduino. (Rule LP057)

Signed-off-by: Frederic Pillon <frederic.pillon@st.com>

Author: fpistm

libraries/Servo/library.properties

@@ -1,8 +1,8 @@
 name=Servo
 version=1.1.2
 author=Michael Margolis, Arduino
-maintainer=Arduino <info@arduino.cc>
-sentence=Allows Arduino/Genuino boards to control a variety of servo motors.
+maintainer=stm32duino
+sentence=Allows Arduino/Genuino and STM32 based boards to control a variety of servo motors.
 paragraph=This library can control a great number of servos.<br />It makes careful use of timers: the library can control 12 servos using only 1 timer.<br />On the Arduino Due you can control up to 60 servos.<br />
 category=Device Control
 url=http://www.arduino.cc/en/Reference/Servo