Update getusermedia.html

Co-authored-by: youennf <[email protected]>

getusermedia.html

@@ -1774,7 +1774,7 @@ <h2>Constrainable Properties</h2>
             <tr id="def-constraint-frameRate">
               <td><dfn>frameRate</dfn></td>
               <td>{{ConstrainDouble}}</td>
-              <td><p>The exact frame rate (frames per second) or frame rate range.
+              <td><p>The frame rate (frames per second) or frame rate range.
               If video source's pre-set can determine frame rate values, the range, as a capacity,
               should span the video source's pre-set frame rate values with
               min being equal to 0 and max being the largest frame rate.