ccmain/paragraphs: Fix memory leak

Coverity report:

CID 1164737 (#1 of 1): Resource leak (RESOURCE_LEAK)
49. leaked_storage: Variable p going out of scope leaks the storage it points to.

Signed-off-by: Stefan Weil <sw@weilnetz.de>

ccmain/paragraphs.cpp

@@ -2113,6 +2113,7 @@ void ConvertHypothesizedModelRunsToParagraphs(
       if ((*row_owners)[row] != NULL) {
         tprintf("Memory leak! ConvertHypothesizeModelRunsToParagraphs() called "
                 "more than once!\n");
+        delete (*row_owners)[row];
       }
       (*row_owners)[row] = p;
     }