Quoted param value in Solr query to avoid unwanted traces in logs

When Webgraph Solr core is enabled, crawling and removing from index an
URL whose hash starts with the '-' character (example URL :
https://cs.wikipedia.org/ whose hash is "-2-HuTEndn4x") produced a full
ParseException stack trace in YaCy logs. This was not blocking because
the Solr query parser is able to escape itself the query and run it
successfully, but filled uselessly YaCy logs.

source/net/yacy/search/index/Fulltext.java

@@ -504,7 +504,8 @@ public final class Fulltext {
             this.getDefaultConnector().deleteByIds(deleteIDs);
             if (this.writeWebgraph) { // Webgraph.id is combination of sourceHash+targetHash+hexCounter, to be successful use source_id_s and/or target_id_s
                 for (String id : deleteIDs) {
-                    this.getWebgraphConnector().deleteByQuery(WebgraphSchema.source_id_s.name() + ":" + id);
+                	/* Add quotes around the url hash to prevent Solr logging a ParseException stack trace when the hash start with a '-' character */
+                    this.getWebgraphConnector().deleteByQuery(WebgraphSchema.source_id_s.name() + ":\"" + id  + "\"");
                 }
             }
         } catch (final Throwable e) {
@@ -524,7 +525,8 @@ public final class Fulltext {
             String id = ASCII.String(urlHash);
             this.getDefaultConnector().deleteById(id);
             if (this.writeWebgraph) { // Webgraph.id is combination of sourceHash+targetHash+hexCounter, to be successful use source_id_s and/or target_id_s
-                this.getWebgraphConnector().deleteByQuery(WebgraphSchema.source_id_s + ":" + id);
+            	/* Add quotes around the url hash to prevent Solr logging a ParseException stack trace when the hash start with a '-' character */
+                this.getWebgraphConnector().deleteByQuery(WebgraphSchema.source_id_s + ":\"" + id + "\"");
             }
         } catch (final Throwable e) {
             ConcurrentLog.logException(e);