settings: Set the default width of the sidebar to 170

The current setting of 148 causes text like "Downloads" to be ellipsized by
default. Up the size some to prevent this.

Author: JosephMcc

libnemo-private/org.nemo.gschema.xml

@@ -592,7 +592,7 @@
       <description>Whether the navigation window should be maximized by default.</description>
     </key>
     <key name="sidebar-width" type="i">
-      <default>148</default>
+      <default>170</default>
       <summary>Width of the side pane</summary>
       <description>The default width of the side pane in new windows.</description>
     </key>