AM, NFM and WFM modulators: changed mute/umute channel button icon

plugins/channeltx/modam/ammodgui.ui

@@ -169,15 +169,15 @@
         <item>
          <widget class="QToolButton" name="channelMute">
           <property name="toolTip">
-           <string>Mute/Unmute audio</string>
+           <string>Mute/Unmute channel</string>
           </property>
           <property name="text">
            <string>...</string>
           </property>
           <property name="icon">
            <iconset resource="../../../sdrbase/resources/res.qrc">
-            <normaloff>:/sound_on.png</normaloff>
-            <normalon>:/sound_off.png</normalon>:/sound_on.png</iconset>
+            <normaloff>:/txon.png</normaloff>
+            <normalon>:/txoff.png</normalon>:/txon.png</iconset>
           </property>
           <property name="checkable">
            <bool>true</bool>

plugins/channeltx/modnfm/nfmmodgui.ui

@@ -169,15 +169,15 @@
         <item>
          <widget class="QToolButton" name="channelMute">
           <property name="toolTip">
-           <string>Mute/Unmute audio</string>
+           <string>Mute/Unmute channel</string>
           </property>
           <property name="text">
            <string>...</string>
           </property>
           <property name="icon">
            <iconset resource="../../../sdrbase/resources/res.qrc">
-            <normaloff>:/sound_on.png</normaloff>
-            <normalon>:/sound_off.png</normalon>:/sound_on.png</iconset>
+            <normaloff>:/txon.png</normaloff>
+            <normalon>:/txoff.png</normalon>:/txon.png</iconset>
           </property>
           <property name="checkable">
            <bool>true</bool>

plugins/channeltx/modwfm/wfmmodgui.ui

@@ -169,15 +169,15 @@
         <item>
          <widget class="QToolButton" name="channelMute">
           <property name="toolTip">
-           <string>Mute/Unmute audio</string>
+           <string>Mute/Unmute channel</string>
           </property>
           <property name="text">
            <string>...</string>
           </property>
           <property name="icon">
            <iconset resource="../../../sdrbase/resources/res.qrc">
-            <normaloff>:/sound_on.png</normaloff>
-            <normalon>:/sound_off.png</normalon>:/sound_on.png</iconset>
+            <normaloff>:/txon.png</normaloff>
+            <normalon>:/txoff.png</normalon>:/txon.png</iconset>
           </property>
           <property name="checkable">
            <bool>true</bool>

sdrbase/resources/res.qrc

@@ -67,5 +67,7 @@
         <file>slot2_on.png</file>
         <file>iambickey.png</file>
         <file>morsekey.png</file>
+        <file>txoff.png</file>
+        <file>txon.png</file>
     </qresource>
 </RCC>