Float is a nullable type, prevent NPE (part 2)

Author: Brutus5000

src/main/java/com/faforever/api/data/domain/GameReviewsSummary.java

@@ -60,7 +60,7 @@ public float getLowerBound() {
   }
 
   @Column(name = "average_score")
-  public float getAverageScore() {
+  public Float getAverageScore() {
     return averageScore;
   }
 

src/main/java/com/faforever/api/data/domain/MapReviewsSummary.java

@@ -64,7 +64,7 @@ public Float getLowerBound() {
   }
 
   @Column(name = "average_score")
-  public float getAverageScore() {
+  public Float getAverageScore() {
     return averageScore;
   }
 

src/main/java/com/faforever/api/data/domain/ModReviewsSummary.java

@@ -64,7 +64,7 @@ public Float getLowerBound() {
   }
 
   @Column(name = "average_score")
-  public float getAverageScore() {
+  public Float getAverageScore() {
     return averageScore;
   }
 

src/main/java/com/faforever/api/data/domain/ModVersionReviewsSummary.java

@@ -64,7 +64,7 @@ public float getLowerBound() {
   }
 
   @Column(name = "average_score")
-  public float getAverageScore() {
+  public Float getAverageScore() {
     return averageScore;
   }