use manual gain mode by default

apps/osmosdr_source.grc

@@ -1,6 +1,6 @@
 <?xml version='1.0' encoding='ASCII'?>
 <flow_graph>
-  <timestamp>Sat May  5 00:40:44 2012</timestamp>
+  <timestamp>Sat May  5 14:59:24 2012</timestamp>
   <block>
     <key>options</key>
     <param>
@@ -470,7 +470,7 @@
     </param>
     <param>
       <key>gain_mode1</key>
-      <value>0</value>
+      <value>1</value>
     </param>
     <param>
       <key>ant1</key>

grc/gen_osmosdr_blocks.py

@@ -131,7 +131,8 @@ Overall gain of the device's signal path. For the gain setting to apply the
 manual gain mode must be enabled first for some devices (namely rtlsdr).
 
 Gain Mode:
-Chooses between the automatic (default) and manual gain mode where appropriate.
+Chooses between the manual (default) and automatc gain mode where appropriate.
+Currently, only rtlsdr devices support automatic gain mode.
 
 Antenna:
 For devices with only one antenna, this may be left blank.
@@ -171,14 +172,14 @@ PARAMS_TMPL = """
 		<value></value>
 		<type>enum</type>
 		<hide>\#if \$nchan() > $n then 'none' else 'all'#</hide>
-		<option>
-			<name>Auto</name>
-			<key>0</key>
-		</option>
 		<option>
 			<name>Manual</name>
 			<key>1</key>
 		</option>
+		<option>
+			<name>Auto</name>
+			<key>0</key>
+		</option>
 	</param>
 	<param>
 		<name>Ch$(n): Antenna</name>