revert incorrect typo fix

Co-authored-by: A Thousand Ships <96648715+AThousandShips@users.noreply.github.com>

doc/classes/AudioEffectFilter.xml

@@ -14,7 +14,7 @@
 			Threshold frequency for the filter, in Hz.
 		</member>
 		<member name="db" type="int" setter="set_db" getter="get_db" enum="AudioEffectFilter.FilterDB" default="0">
-			Steepens of the cutoff curve in dB per octave, also known as the order of the filter. Higher orders have a more aggressive cutoff.
+			Steepness of the cutoff curve in dB per octave, also known as the order of the filter. Higher orders have a more aggressive cutoff.
 		</member>
 		<member name="gain" type="float" setter="set_gain" getter="get_gain" default="1.0">
 			Gain amount of the frequencies after the filter.