improve NPE chance on missing parameters

java.lang.NullPointerException
	at net.yacy.http.servlets.SolrServlet.service(SolrServlet.java:145)
	at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:684)
	at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:501)

source/net/yacy/http/servlets/SolrServlet.java

@@ -141,12 +141,12 @@ public class SolrServlet extends HttpServlet {
             }
             String q = mmsp.get(CommonParams.Q, "");
             if (querystring.length() == 0) querystring = q;
-            if (!mmsp.getMap().containsKey(CommonParams.START)) {
+            if (!mmsp.getMap().containsKey(CommonParams.START) && mmsp.getMap().containsKey("startRecord")) {
                 int startRecord = mmsp.getFieldInt("startRecord", "0");
                 mmsp.getMap().remove("startRecord");
                 mmsp.getMap().put(CommonParams.START, new String[]{Integer.toString(startRecord)}); // sru patch
             }
-            if (!mmsp.getMap().containsKey(CommonParams.ROWS)) {
+            if (!mmsp.getMap().containsKey(CommonParams.ROWS) && mmsp.getMap().containsKey("maximumRecords")) {
                 int maximumRecords = mmsp.getFieldInt("maximumRecords", "10");
                 mmsp.getMap().remove("maximumRecords");
                 mmsp.getMap().put(CommonParams.ROWS, new String[]{Integer.toString(maximumRecords)}); // sru patch