glyphicons.less: lowercase F in codepoint number for consistency

less/glyphicons.less

@@ -239,7 +239,7 @@
 .glyphicon-copy                   { &:before { content: "\e205"; } }
 .glyphicon-paste                  { &:before { content: "\e206"; } }
 .glyphicon-door                   { &:before { content: "\1f6aa"; } }
-.glyphicon-key                    { &:before { content: "\1F511"; } }
+.glyphicon-key                    { &:before { content: "\1f511"; } }
 .glyphicon-alert                  { &:before { content: "\e209"; } }
 .glyphicon-equalizer              { &:before { content: "\e210"; } }
 .glyphicon-king                   { &:before { content: "\e211"; } }