Removed invalid empty form action.

A form action URL must not be empty (see
https://www.w3.org/TR/html/sec-forms.html#element-attrdef-form-action ).
No action attribute has the same effect (relaunching the same GET
action) but is valid HTML.

htroot/yacysearch.html

@@ -89,7 +89,7 @@ Use the RSS search result format to add static searches to your RSS reader, if y
   <div class="row">
     <div class="col-sm-8 col-sm-offset-4 col-md-9 col-md-offset-3 main">
 
-<form class="search small" name="searchform" action="" method="get" accept-charset="UTF-8" style="position:fixed;top:8px;z-index:1052;max-width:500px;">
+<form class="search small" name="searchform" method="get" accept-charset="UTF-8" style="position:fixed;top:8px;z-index:1052;max-width:500px;">
 
   <div class="input-group">
     <input name="query" id="search" type="text" class="form-control searchinput typeahead" size="40" maxlength="200" placeholder="#[promoteSearchPageGreeting]#" value="#[former]#" #(focus)#::autofocus="autofocus"#(/focus)# onFocus="this.select()" onclick="document.getElementById('Enter').innerHTML = 'search'"/>