Fix typo in string solver string preprocessing

The typo prevented CProverString.deleteCharAt(StringBuffer) from being replaced
by the corresponding string solver primitive.

Author: danpoe

jbmc/src/java_bytecode/java_string_library_preprocess.cpp

@@ -1507,7 +1507,7 @@ void java_string_library_preprocesst::initialize_conversion_table()
       ID_cprover_string_delete_func;
   cprover_equivalent_to_java_assign_and_return_function
     ["java::org.cprover.CProverString.deleteCharAt:(Ljava/lang/"
-     "StringBufferI)Ljava/lang/StringBuffer;"] =
+     "StringBuffer;I)Ljava/lang/StringBuffer;"] =
       ID_cprover_string_delete_char_at_func;
   cprover_equivalent_to_java_assign_and_return_function
     ["java::org.cprover.CProverString.deleteCharAt:(Ljava/lang/"